NA TURE 



[November 24, 1898 



developed inlo upland running types, which competed with the 

 Horses and Ruminants of the plains ; while others were more 

 likely frequenters of marshes and river-banks, like many of the 

 Rhinoceroses of the present day. Neither the Hyracodonts or 

 the Amynodonts ever developed horns, and all the early species 

 of true Rhinoceroses had weak, hornless nasal lx)nes,so that in ex- 

 ternal appearance they were probably more like large-sized Tapirs 

 than the well-armed animals with which we are now familiar. 



"They did not interfere with each other," writes the author, 

 " because each enjoyed a different local habitat while occupying 

 the same general geographical regions. The Hyracodonts dwelt 

 in the drier grassy plains. The Amynodonts frequented the 

 river and lake borders. Up to the time of the extinction of 

 these two related families, the true Rhinoceroses maintained a 

 somewhat uniform structure, both in Europe and America, 

 differing so far as we know in size rather than in proportions. 

 Their dentition and their feeding habits were probably similar 

 to those of the A', bicornis of Africa, and the A", snmalrensis and 

 K. sondaiciis of Asia, namely upon shrubs, leaves, and softer 

 herbage. After the extinction of the rival families, however, 

 there was naturally a tendency on the part of the true Rhin- 

 oceroses to enter the peculiar local habitats previously occupied 

 by the Hyracodonts and Amynodonts, and they accordingly 

 diverged into upland and lowland, short and long-limbed, 

 brachydont and hypsodont types." 



From this it will be evident that Prof. Osborn by no means 

 confines himself to the dry details considered sufficient by so many 

 palasonlologists, but endeavours to give his readers a mental 

 picture of the habits of the animals he so well describes. He 

 next proceeds to show that the Nhinoierotida, or true Rhin- 

 oceroses, diverged into four sub-families. These are, first, the 

 Attrtukeriime, or Hornless Rhinoceroses ; second, the Dicer- 

 atheriina, or Transversely- horned Rhinoceroses ; third, the 

 Rhiiwcerotintc, or typical Rhinoceroses ; and, fourth, the 

 ElasmotheriintT, represented only by the huge Elasmotherium 

 of Siberia. And he further shows that while the first and 

 second of these, like the Hyracodonts and Amynodonts, are 

 common to the Old and New Worlds, the third and fourth are 

 exclusively Old World types. 



In the New World the Rhinoceroses Ijecame entirely extinct 

 at the close of the Miocene period ; and this, although it is not 

 mentioned by the author, is doubtle.ss the reason they never 

 penetrated into South America, which up to that date was cut 

 off from North America. No reason can at present be assigned 

 for the sudden extinction of the group in North America, seeing 

 that a profusion of animals, adapted apparently for a warm 

 climate, flourished there during the Pliocene ; while the case of 

 the Woolly Rhinoceros and the Elasmothere indicates that the 

 Rhinoceroses them.selves were capable of fitting themselves to 

 withstand subarctic conditions. 



Whether the group first originated in the Eastern or the 

 Western Hemisphere, the author, perhaps wisely, refrains from 

 discussing. In both regions they appear to have come into 

 existence at approximately the same period ; and in both, up to 

 a certain stage, they seem to have undergone a parallel develop- 

 ment. This, as in the case of the Horses, would seem to sug- 

 gest that during the middle portion of the Tertiary epoch the 

 connection between the Old and the New Worlds was much 

 more extensive than a mere narrow bridge across Bering Strait. 

 But, on the other hand, the existence of large groups like the 

 Civets and Hyxnas which never succeeded in travelling from 

 the Eastern to the Western Hemisphere, is, so far as it goes, 

 in favour of "only a narrow connection in high latitudes. 



As already mentioned, the author includes all the typical 

 Rhinoceroses in a single sub-family or group. On p. 84 this 

 group is correctly termed Khinoceroliiut, but in the table on 

 p. 121 it is renamed Ceralorhina, which is obviously wrong. As 

 with the Aicralheriitur, the author considers that the group may 

 be divided inlo a Dolichocephalic and a Brachycephalic section. 

 The former section is taken to include all the Pliocene and 

 Plistocene Old World s|x:cies, with the exception of the Pikermi 

 K. pathygnatlius ; while the latter embraces the .Miocene and 

 recent Old World types, except the living h'. sumatrelisis. To 

 this classification we must take one exception. In our opinion 

 the African "White Rhinoceros" (K. siniiis) is as dolicho- 

 cephalic as the Plistocene A'. anli,/uilatis. The figure of the 

 skull of the former, which the author has copied from some 

 previous writer, is misleading ; and if he had the opportunity of 

 seeing the fine series of siwcimens in the British Museum, he 

 Would in all probability amend the statement. 



NO. 151 7, VOL. 59] 



Space prevents detailed notice of the interesting observations 

 which the author gives on the evolution of the cheek-teeth ia 

 the group. It may, however, be observed that he is in accord 

 with previous writers in regarding the white and woolly Rhin- 

 oceroses as presenting the culminating point of molar evolution 

 among the typical Kliinoceroses ; Elasmolherium representing 

 a still more specialised offshoot by itself. .\t present we are 

 left in some degree of doubt as to the author's views with regard 

 to the generic or subgeneric divisions of the Plistocene and 

 recent Rhinoceroses ; but light will probably be thrown upoii 

 this point as the work proceeds. So far as Ihey have been 

 carried at present Prof. Osborn's labours afford, in the main, a 

 distinct advance in our knowledge of a very interestit>g group, 

 and the completion of his memoir will be anxiously awaited by 

 all who have made the subject a special study. R. L. 



THE BRITISH ASSOCIATION. 



BRISTOL MEETING. 



Section K (Botany). 



Opening Address bv Prof. F. O. Bower, St.D., F.R.S., 



President of the Section.' 



IL 



I. Algae and Fungi. 



A T first sight those Algae and Phycomycelous Fungi w hicb 

 ■'"*• show a subdivision of the zygote appear to offer the key to 

 the enigma of the first start of antithetic alternation, and such 

 rudimentary fruit-bodies as those of Oedogoniuvt and Coleochaete 

 are frequently quoted as prototypes of sporogonia. My own 

 position has been that they may be "accepted as suggestive of 

 similar progress in the course of evolution of Vascular Plants." 

 On the assumption that the zygote is equivalent in all cases — 

 and this is itself a pure assumption — the fruit-body of such Algae 

 or Fungi would be comparable to the sporophyte in higher 

 forms ; but it must be clearly remembered that it is not evet> 

 then proved to be hoiiiogenetk. Dr. Scott has based a strong 

 line of criticism of antithetic views upon these cases. He re- 

 marks : " The sudden appearance of something completely newr 

 in the life-history, as required by the antithetic theory, has, to 

 my mind, a certain improbability. E.\ nihilo nihil fit. We 

 are not accustomed in natural history to see brand new structures 

 appearing, like morphological Melchisedcks, without father or 

 mother. Nature is conservative, and when a new organ is to be 

 formed it is, as every one knows, almost always fashioned out of 

 some pre-existing organ. Hence I feel a certain difficulty in 

 accepting the doctrine of the appearance of an intercalated 

 sporophyte by a kind of special creation." 



In answer to this, I state that to me the zygote, from which 

 our hypothesis starts, is not "nothing " ; it is a cell with all the 

 powers and pos.sibilities of a complete cell. Vochting, in his 

 " Organbildung," has fairly concluded that " a living vegetative 

 cell which is capable of growth has not 3 specific and unalterable 

 function." I have myself demonstrated that cells typically 

 sporogenous may develop as vegetative tissue, and conversely 

 that tissues normally vegetative may on occasions become sporo- 

 genous. We may, therefore, say generally as regards the sporo- 

 phyte, that "a living cell which is capable of growth has not a 

 specific and unalterable function." This I conceive to have 

 been the condition of the zygote, and of its early products. 



I think that the words "intercalation" or "interpolation," 

 as used by writers on antithetic alternation, have been quite 

 misunderstood. I have contemplated no sudden development — 

 indeed, on the first page of my " Studies " I have spoken of the 

 sporophyte as "gradually " interpolated. Nor is the suggested 

 development something "completely new," for I specially s|)eak 

 of el.tboration of the zygote. This is the iiarent of these "mor- 

 phological Melchisedeks " ; and unless segmentation be held to 

 be synonymous with " special creation," I confess I do not see 

 where the initial difficulty arises. I agree that nature is con- 

 servative ; what we contemplate is the fa.shioning of the s|X>ro- 

 phyte by a process of which the first step is segnientation, out 

 of a pre-existing organ the zygote. Such simple segmentation 

 is seen in the case of certain Algae and Fungi, and these may be 

 taken as suggesting how the sporophyte of the .Archegoniatae 

 may have come to be initiated. But I am not aware of having 

 ever suggested that these segmented zygotes of .Algae are the 

 homogenetic prototypes of the more elaborate sporophytes. 

 1 Continued from p. 69. 



