FOREST AND STREAM. 



%%6 



capturing a bass every few yards. HIg. was iu the prow, and 

 caught every fisli that was taken, the- Undersigned riot having 

 occasion to use the second minnow that forenoon. As the 

 clatter of the Svagon could nol be heard at noon, we concluded 

 that Mack had persuaded Ben to put up and feed his horses 

 and let us walk back— of which we knew him capable— so we 

 gave our catch to the Oarsman for Ins services, hastily packed 

 "P and started back heavily loaded with traps piSksd up at 

 points along the bank, where they had been left for conven- 

 ience and remained uninterrupted except by our orders since 

 the afternoon of our arrival. We were unjust to Mac!.:, for 

 the wagon was heard comiug before we came in sight of Die 

 house, but met too near the yard fence to be of any service. 

 We tmtnd dinner steaming upon the table, and discovered 

 that Mack had killed enough good ones for that meal, and 

 gotten iu soon enough to have them served. Ren had the 

 freight loaded, &ad steam up by two o'clock, and when he 

 yelled "All aboard !" we had bidden adieu to our big hearted 

 host and family, and Were prepared for the jolt. 



Thinking to surprise us by a wonderful improvement in seats, 

 P.en had seriously aggravated the abominations of that road 

 by substituting chairTfor the cross-plank seats on which we 

 rode op, and the fearful recklessness with which we slipped 

 about, jeopardizing legs, buckets and rods, demanded that a 

 halt lie called, bark procured, and those chairs secured to the 

 sides of the wagon bed. Whether or not Ben was so improv- 

 ident as to come off again without a pint, was not ascertained; 

 hut he didn't forget to bring his diminutive boy of six years! 

 "just to please him," and, as it turned out, to keep us in 

 constant dread of unavoidably giving occasion for a first 

 class funeral at Ben's, by crushing the life out of the boy. 



We were returned to Livingston in thirty minutes less time 

 than it required Ben to take us up. 



Aside from the wagon rides, our trip was a delightful one, 

 which we hope to repeat annually for the next hundred years, 

 and hope those few lines may find the editors and numberless 

 readers of the F. ifc S. enjoying a similar blessing. 



Tin an. 



INTRODUCTION AND SUCCESSION OF 

 VERTEBRATE LIFE IN AMERICA.* 



Bv Puok. O. 0. Marsh. 

 pke3itjest op the biological section of the american 



association. 



Seventh Papee. 



T 1ST this rapid review of Mammalian life in America, from its 

 J- first known appearance in the Trias down to the present 

 time, I have endeavored to state briefly the introduction and 

 succession of the principal forms in each natural group. If 

 time permitted, I might attempt the more difficult task of try- 

 ing to indicate what relation these various groups may possi- 

 bly bear to each other ; what connection the Ancient Mam- 

 mals of this continent have with the corresponding forms of 

 the Old World j and, most important of all, what real progress 

 Mammalian life has here made since the beginning of the Eo- 

 cene. As it is, I can only say in summing up, that the Mar- 

 supials are clearly the remnants of a very ancient fauna, 

 which occupied this continent millions of years ago, and from 

 which the other Mammals were doubtless all derived, although 

 the direct evidence of this transformation is wanting. 



Although the Marsupials are near^ related to the still lower 

 Monotretnes, now living in the Australian Region, we have as 

 yet no hint of the path by which the two groups became sep- 

 arated from the inferior vertebrates. Neither have we to-day 

 much light as to the genetic connection existing between Mar- 

 supials and the placental Mammalia, although it is possible 

 that the different orders of the latter had their origin each 

 from a separate group of Marsupials. 



The presence, however, of undoubted Marsupials in our low- 

 er and middle Eocene, some of them related to the genus Di- 

 delphys, although remotely, is important evidence as to the in- 

 t reduction of these animals in America. Against this their 

 supposed absence in our Miocene and Pliocene can have but 

 limited Weight when taken in connection with the fact that 

 they flourished in the Post-Tertiary, aud are still abundant. 

 The evidence we now have is quite as strongly in favor of a 

 migration of Marsupinls from America to the Old World, as 

 the reverse, which has been supposed by s >me naturalists. 

 Possibly, as Huxley suggested, both countries were peopled 

 with the low Mammals from a continent now submerged. 



The Edentate mammals have long been a puzzle to Zoolo- 

 gists, and up to the preseutfimeno clew to their affinities with 

 other groups seems to have been detected. A comparison of 

 the peculiar Eocene Mammals, which 1 have called the Tillo- 

 dontkt, with the least specialized Edentates, brings to light 

 many curious resemblances in the skull, teeth, skeleton and 

 feet. These suggest relationship, at least, and possibly we 

 may yet find here the key to the Edentate genealogy. At 

 present, the Tillodonts are all from the lower and middle 

 Eocene, while mbrqpm, the oldest edentate genus, is found in 

 the middle Miocene, and one species in the lower Pliocene. 



The Edentates have been usually regarded as an American 

 type, but the few living forms iu Africa, and the Tertiary 

 species in Europe, the oldest known, have made the land of 

 their nativity uncertain. I have already given yon some 

 reasons for believing that the Edentates had their first home 

 iu North America, and migrated thence to the southern portion 

 of the continent. This movement could not have taken place 

 in the Miocene period, as the Isthmus of Darien was then sub- 

 merged ; but near the close of the Tertiary, the elevation of 

 this region left a much broader strip of land than now exists 

 there, and over this, the Edentates and other mammals made 

 their way, perhaps uiged on by the increasing cold of the 

 glacial winters. The evidence to-day is strongly in favor of 

 such a southern migration. This, however, leaves the Old 

 World Edentates, fossil and recent, unaccounted for • but I 



1 l:,.^.^. ll<n nAllli'imi J"\f tKlQ FIH/aHI/J^M 1« .-inn.-, «-, I- t .-. "I 1 _. i t_ .- 



♦ Delivered before tlie American Association for tue Advancement of 

 Science, at Nashville, Tenn., Aug 31, 1877. 



enough, are more like the latter aud the existing African 

 types than like any of our living species. If, now, we bear in 

 mind that an ebvatiou of only 180 feet would, as Dana has 

 said, close Behring's Straits, and give a road thirty miles wide 

 from America to Asia, we can easily see how this migration 

 might have taken place. That such a Tertiary bridge did 

 exist, we. have much independent testimony, and the known 

 facts all point to extensive migrations of animals over it. 



The Getam are connected with the marine Carnivores 

 through the genus Zeuglodon, as Huxley has shdwn, and the 

 points of resemblance are so marked that the affinity cannot 

 be doubled. That the.connecdon was a direct oue, is hardly 

 probable, since the diminutive brain, large number of simpie 

 teeth, and reduced limbs in the Whales, all indicate them 

 to. Be an old type, which doubtless branched off from the more 

 primitive stock leading to the Carnivores. Our American ex- 

 tinct Cetaceans, when carefully investigated, promise to 

 throw much light upon the pedigree of these strange mam- 

 mals. As most the known forms were probably marine, their 

 distribution is of little service in determining their origin 



J hat the Sireniaus are allied to the Ungulates, is now gen- 

 erally admitted by anatomists, and the separation of the exist- 

 ing species in distant localities suggests that they are the 

 remnants of an extensive group, once widely distributed. The 

 huge number of teeth m Borne forms, the reduced limbs and 

 Other characters, point back to an ancestry near that of the 

 earliest ungulates. The gradual loss of teeth in the specialized 

 members of this group, and in the Cetaceans, is quite parallel 

 with the same change iu Edentates, as well as in Pterodactyls 

 and Birds. J 



The Ungulates are so distinct from other groups that they 

 must be one of the oldest natural divisions of mammals, and 

 they probably originated from some herbivorous marsupial. 

 Iheir large size, and great numbers during Tertiary and Posl- 

 ferliary time, render them most valuable in tracing migrations 

 induced by climate, as well as in showing the changes of 

 structure winch such a contest for existence may produce. 



In the review of the extinct Ungulates, 1 have endeavored 

 to show that quite a number of genera usually supposed to be- 

 long originally to the Old World arc in reality true American 

 types. Among these were the Horse. Rhinocerous and Tapir 

 all the existing odd toed Ungulates, and besides these 

 the Camel, Pig and Deer. All these I believe, and many 

 others, went to Asia from our Northwest Coast. It must, for 

 the present, remain an open question whether we may not 

 fairly claim the liovida, and even the Proboacidm, since both 

 occur iu our strata at about the same horizon as on the other 

 continent. On this point there is some confusion, at least in 

 names. The Himalayan deposits called Upper Miocene, and 

 so rich in Proboscidians, indicate in their entire fauna that 

 they arc more recent than our Niobrara liiver beds, which, 

 for apparently good reasons, we regard as Lower Plioceuc 

 Ihe latter appear to be about the same horizon as the Piker- 

 uu deposits in Greece, also regarded as Miocene. Believing 

 however, that we have here a more complete Tertiary series' 

 and a better standard for comparison of faunas, I have pre- 

 ferred to retain the names already applied to our divisions, 

 until the strata of the two continents are more satisfactorily 

 co-ordinated. 



The extinct Rodents, Bats and Insectivores of America 

 although offering many suggestive hints as to their relation- 

 ship with other groups and their various migrations, cannot 

 now be fully discussed. There is little doubt, however, that 

 the Rodents are a New World type, and, according to present 

 evidence, they probably had their origin in North America 

 ihe resemblance m so many respects of this order to the Pro- 

 boscideans is a striking fact, not yet explained by the imper- 

 fectly known genealogy of either group. 

 _ The Carnivores, too, I must pass by, except to call atten- 

 tion to a few special forms which accompanied the migrations 

 of other groups. One of these is Machairodm, the saber- 

 toothed Tiger, which flourished in our Miocene and Pliocene 

 and followed the huge Edendates to South America, and the 

 Ungulates across Asia to Europe. With this genus went 

 Hyanodon, and some typical Wolves and Cats, but the Bears 

 came the other way with the Antelopes. That the Gazelle, 

 (jriraile, Hippopotamus, Hyaena and other African types 

 once abundant iu Asia, did not come, is doubtless because 

 the Miocene bridge was submerged before they reached it. 



The Edentates, in their southern migration, were probably 

 accompanied by the Horse, Tapir and Rhinoceros, although 

 no remains of the last have yet been found south of Mexico 

 The Mastodon, Elephant, Llama, Deer, Peccary, and other 

 mammals, followed the same path. Why the Mastodon, 

 Elephant, Rhinoceros, aud especially the Horse, should have 

 been selected with the large Edentates for extinction, ana the 

 other Ungulates left, is at present a mystery, which their 

 somewhat larger size hardly explains. 



The relations of the American primates, extinct and recent 

 to those of the other hemisphere, offer an inviting topic, but 

 it is not iu my present province to discuss them in their most 

 suggestive phases. As we have here the oldest and most gen- 

 eralized members of the group, so far as now known, we may 

 justly claim America for the birth-place of the order. That 

 the development did not continue here until it culminated in 

 Man, was due to causes which at present we can only surmise 

 although the genealogy of other surviving groups gives some 

 data toward a solution. Why the Old World Apes, when dif- 

 ferentiated, did not come to the land of their earlier ancestry 

 is readily explained by the then intervening oceans, which 

 likewise were a barrier to the return of the Horse and Rhi- 

 noceros. 



Man, however, came; doubtless first across Behrings 

 Straits ; and at his advent became part of our fauna, as a 

 mammal and primate, In these relations alone, it is mv pur- 

 pose here to treat him. The" evidence, as it stands to-day 

 although not conclusive, seems to place the first appearance 

 of Man in tins country in the Pliocene, and the best proof of 

 this has been found on the Pacific coast. During several 

 visits to that region, many facts were brought to my knowl- 

 edge which render this more than probable. Man at this 

 time was a savage, and was doubtless forced by the great vol- 

 canic outbreaks to continue his migration. This was at firs 

 to the south, since mountain chains were barriers on the east. 

 As the native Horses of America were now all extinct, and as 

 the early man did not bring the Old World animal with him, 

 his migrations were slow. I believe, moreover, that this slow- 

 progress toward civilization was in no small degree due to this 

 same cause— the absence of the Horse. 



It is far from uiy intention to add to the many theories ex- 

 tant in regard to the early civilizations iu this country, and 

 their connections with the primitive inhabitants, or the later 

 Indians, but two or three facts have recently come to my 

 knowledge which i. think worth mentioning in this connection 

 On the Columbia River, I have found evidence of the former 

 existence of inhabitants much superior to the Indians at pres- 

 ent there, and of which no tradition remains. Among many 



stone carvings which I saw there, were a number of heads 

 which so strongly resemble those of Apes, that the likeness at 

 once suggests itself. Whence came these sculptures, and by 

 whom were they made ? Another fact that has interested me 

 very much is the strong resemblance between the skulls of the 

 typical Mound-builders of the Mississippi Valley and those of 

 the Pueblo Indians. 1 had long been familiar with the for- 

 mer, and when 1 recently saw the latter, it required the posi- 

 tive assurance of a friend whodiad himself collected them in 

 New Mexico, to convince me that they were not from the 

 mounds. A third fact, and I leave Man to the Archaeologists, 

 on whose province 1 am even now trenching. In a large col- 

 lection of Mound- builders' pottery, over a thousand specimens 

 which I have recently examined with some care, I found 

 many pieces of elaborate workmanship so nearly like the. 

 ancient water- jars from Peru, that no one could fairly doubt 

 that some intercourse had taken place between the widely 

 separated people that made them. 



The oldest known remains of Man on this continent differ 

 in no important characters from the bones of the typical In- 

 dian, although in some minor details they indicate a much 

 more primitive race. These early remains', some or which are 

 true fossils, resemble much more closely the corresponding 

 parts of the highest Old World Apes, than do the latter our 

 Tertiary Primates, or even the recent American Monkeys. 

 Various living aud fossil forms of Old world Primates fill up 

 essentially the latter gap. The lesser gap between the prim- 

 itive Man of America and the Anthropoid Apes is partially 

 closed by still lower forms of men, and doubtless also by 

 higher Apes, now extinct. Analogy, and many facts as 

 well, indicate that this gap was smaller in the past It 

 certainly is becoming wider now with every generation, 

 for the lowest races of men will soon become extinct, like 

 the Tasmanians, and the highest Apes caunot long sur- 

 vive. Hence the intermediate forms of the past, if any 

 there were, become of still greater importance. For such 

 missing links, we must look to the caves and later Tertiary 

 of Africa, which I regard as now the most promising field 

 for exploration in the Old World. America, even in the 

 Tropics, can promise no such inducements to ambitious ex- 

 plorers. We have, however, an equally important field, if 

 less attractive, in the Cretaceous Mammals, which must have 

 left their remains somewhere on this continent. In these two 

 directions, as I believe, lie the mo3t important future discov- 

 eries in Palaeontology. 



As a cause for many changes of structure in mammals dur- 

 ing the Tertiary and Post-Tertiary, I regard, as the most 

 potent, Natural Selection, in the broad sense in which that 

 term is now used by American evolutionists. Under this 

 head, I include not' merely a Malthusiau struggle for life 

 amoug the animals themselves, but the equally important 

 contest with the elements, and all surrounding nature. By 

 changes in the environment, migrations are enforced, slow- 

 ly in some cases, rapidly in others, and with change of 

 locality must come adaptation to new conditions, or extinc- 

 tion. _ The life-history of Tertiary mammals illustrates this 

 principle at every stage, and no other explanation meets 

 the facts. 



The real progress of mammalian life in America from the 

 beginning of the Tertiary to the present, is well illustrated by 

 the Brain-growth, in which we have the key to many other 

 changes. The earliest known Tertiary mammals all had very 

 small brains, and in some forms this organ was proportionally 

 less than in certain Reptiles. There was a gradual increase in the 

 size of the brain during this period, and it is interesting to find 

 that this growth was mainly confined to the cerebral hemi- 

 spheres, or higher portion of the brain. In most groups of 

 mammals, the brain has gradually become more convoluted,and ■ 

 thus increased in quality, as weil as quantity. In some, also 

 the cerebellum, aud olfactory lobes, the lower parts of the 

 brain, have even diminished iusize. In the long struggle for 

 existence during Tertiary time, the big brains won, Then as 

 now ; and the increasing power thus gained rendered useless 

 many structures inherited from primitive ancestors, but no 

 longer adapted to new conditions. 



Another of the interesting changes in mammals during Ter- 

 tiary time was in the teeth, which were gradually modified 

 with other parts of the structure. The primitive form of tooth 

 was clearly a cone, and all others are derived from this. All 

 classes of vertebrates below mammals, namely, Pishes Amphi- 

 bians, Reptiles, and Birds, have conical teeth, if any or some 

 simple modification of this form. The Edentates and Ceta- 

 ceans with teeth retain this type, except the Zeuglodonts 

 which approach the dentition of aquatic Carnivores. In the 

 higher mammals, the incisors and canines retain the conical 

 shape, and the premolars have only in part been transformed 

 The latter gradually change to the more complicated molar 

 pattern, and hence are not reduced molars, but transition forms 

 from the cone to more complex types. Most of the early Ter- 

 tiary mammals had forty-four teeth, and in the oldest forms 

 the premolars were all unlike the molars : while the crowns 

 were short, covered with enamel, and without cement. Each 

 stage of progress in the differentiation of the animal was as a 

 rule, marked by a change iu the teeth ; one of the most com- 

 mon being the transfer, iu form at least, of a premolar to the 

 molar series, and a gradual lengthening of the crown. Hence,' 

 it is often easy to decide from a fragment of a jaw, to what 

 horizon of the Tertiary it belongs. The fossil Horses of this 

 period, for example, gained a grinding tooth, for each toe 

 they lost, one in each epoch. In the single-toed existing horses, 

 all the premolars are like the molars, and the process is at an 

 end. Other dental transformations are of equal interest, but 

 this illustration must suffice. 



The changes in the limbs and feet of mammals during the 

 same period were quite as marked. The foot of the primitive 

 mammal was doubtless plantigrade, and certainly five-toed. 

 Many of _ the early Tertiary forms show this feature, which is 

 still seen in some existing forms. This generalized foot became 

 modified by a gradual loss of the outer toes, and increase in 

 size of the central ones; the reduction proceeding according to 

 systematic methods, differing in each group. Corresponding 

 changes took place iu the limb bones. ~Onc result was q great 

 increase inspeed, as the power was applied so as to act "only 

 in the plane of motion. The best effect of this specialization 

 is seen to-day iu the Horse and Antelope, each repmsentin-- c i 

 distinct group ot" Ungulates, with tive-toed ancestors. ' 



If the history of American Mammals, as I have briefly 

 sketched it, seems as a whole incomplete and unsatisfactory 

 we must remember that the genealogical tree of this class has 

 its trunkand larger limbs concealed beneath the debris of Meso ■ 

 zoic time, while its roots doubtless strike so deeply into the 

 Paleozoic that for the present they are lost. A decade or two 

 hence, we shall probably know something of the mammalian 

 fauna of the Cretaceous, and the earlier lineage of our exist inn 

 mammals can theu be traced with more certainty. a 



The results I have presented to you are mainly derived 

 from persona] observation ; and since, a large part of thehiofie 



