August 15, 1878] 



NATURE 



421 



It is curious to find that tlie striking differences between the 

 African and the Indian elephants, now so well understood by 

 every beginner in zoology, and all the facts which have already 

 been accumulated relating to the numerous extinct forms of 

 Proboscideans, whether Mammoths, Mastodons, or Dinotheria, 

 were quite unknown to Linnseus. One species only, Elephas 

 maximus, represented in the zoology of a hundred years ago, 

 was all that was known of the elephants or elephant-like 

 animals. 



The genus Trichechus of this edition exhibits a very curious 

 phase of zoological knowledge. It contains two species, 

 (i) T. rosmarus, the Walrus, now known to be a modified seal, 

 and therefore a member of the Linnsean order Feros, and (2) T. 

 inanatus, a name under which were included all the known 

 forms of Manatees and Dugongs, in fact the whole of the 

 modem order Sirenia ; animals widely removed in all essential 

 points of their organisation from the walrus, with which they 

 are here generically united. Their position, however, between 

 the elephant on the one hand and the sloths on the other, is 

 far better than their association with the Cetacea, as in Cuvier's 

 system, an association from which it has been most difficult to 

 disengage them, notwithstanding their total dissimilarity, except 

 in a few external characters. Although the discovery of many 

 fossil forms has done much to link together the few existing 

 species and to show the essential unity of the group, it has 

 thrown no light upon their origin, or their affinities to other 

 mammals. They still stand, both by their structure and their 

 habits, a strangely isolated group, and it baffles conjecture to say 

 whence they have been derived, or how they have attained their 

 present singular organisation. 



The remaining genera of the Linnasan order Bruia constitute 

 the group out of which Cuvier, following Blumenbach, formed 

 his order Edentata, a name certainly not happily chosen for a 

 division which includes species like the great armadillo, having 

 a larger number of teeth than any other land mammal, but 

 which, nevertheless, has been so generally adopted, and is so 

 well understood, that to attempt to change it would only 

 introduce an element of confusion. Four out of five of the 

 principal modifications of form in the group at present known, 

 are indicated by the four Linnaean genera, Brady pus or Sloth, 

 Myrmecophaga or Ant-eater, Manis or Pangolin, 2SiA Dasypus ox 

 Armadillo. The advances during the century have consisted in 

 the accumulation of a great mass of details respecting these 

 groups, the addition of a fifth and very distinct existing form, 

 the Orycteropus or Cape Anteater, and the discovery of numerous 

 and very remarkable extinct forms, such as the megatheriums 

 and glyptodons of South America, so fully known by their 

 well-preserved osseous remains. There is, however, still much 

 to be done in working out the real relationship of the somewhat 

 isolated members of the order, if it be a natural order, both to 

 each other, and to the rest of the Mammalia, from which they 

 stand widely removed in many points of organisation. 



The third order of Linnreus, Fer^, contained all the then 

 known animals, which, with whatever diversities of general 

 structure, agreed in their predatory habits, and possessed certain 

 general characters of teeth and claws to coirespond, though the 

 terse definition of " Dentes primores superiores sex, aadiusculi, 

 caiiini soliiarii," is by no means universally applicable to them. 

 This order was broken up by Cuvier into the orders Carnivora 

 and Insectivora, and the genus Didelphys, included in it by Lin- 

 nseas, has been since by universal assent removed to another 

 group. 



The first six genera belong to the very well-defined and pro- 

 bably natural group now called Carnivora. The one placed at 

 the head of the list, Phoca, is equivalent to the large and im- 

 portant modern sub-order Pinnipedia, the walrus, however, 

 though essentially a seal, having been, as before mentioned, rele- 

 gated by LinntEus to another order on account of its aberrant 

 dentition. But three species are recorded in the genus. P. 

 ztrsina, the Sea-bear of the North Pacific (now Otaria ursina), 

 P. leonina, founded on Anson's sea-lion, now commonly called 

 the elephant seal, or sea-elephant ^Macrorhinus proboscideus, or 

 more properly leonmns), and P. vitulina, the Common Seal. 



The terrestrial sub-order of Carnivora is represented by five 

 genera, (i) Canis, including the dog, wolf, hyaena, fox, arctic 

 fox, jackal, &c. (2) Felis, with only six species, but still one 

 of the few Linn^an genera, which covers exactly the same 

 ground as at present in the opinion of the majority of zoo- 

 logists, although it may be mentioned as an example of the 

 tendency towards excessive and unnecessary multiplication of 



generic names which exists in some quarters, that it has been 

 divided into as many as fourteen. (3) Viverra, a heterogeneous 

 group, containing ichneumons, coatis, and skunks, animals 

 belonging to three very distinct families, according to modern 

 ideas. (4) Mustela, a far more natural group, being nearly 

 enuivalent to the modern family MustelidcB ; and, lastly, a very 

 comprehensive genus, Ursus, consisting of 6^. meles, the Badger, 

 U, lotor, the Raccoon, U. luscus, the Wolverene,'and all the true 

 bears known, comprised in the single species U. arctos. Many 

 interesting forms of Carnivora, as Cryptopmta, Proteles, Eupleres, 

 Ailurus and Ailuropus, have no place in the Linnsean system, 

 being comparatively modern discoveries. The very recent date 

 (1869) at which the last-named remarkable animal was made 

 known to science by the enterpiising researches of the Abbe 

 David into the fauna of Eastern Thibet, gives hope that we may 

 not yet be at the end of the discovery of even large and hitherto 

 unsuspected forms of existing mammals. 



Next in the Linnsean system comes the genus Didelphys, 

 constituted for the reception of five species of American opos- 

 sums. This is a very interesting landmark in the history of the 

 progress of the knowledge of the animal life of the world, as 

 these five opossums, forming a genus in the midst of the order 

 Ferae, were all that was then known of the great sub-class 

 Marsiipialia, now constituting a group entirely apart from the 

 ordinary members of the class. It is difficult now to imagine an 

 animal world without kangaroos, without wombats, without 

 phalangers, without thylacines, without dasyures, and so many 

 other familiar forms, and yet such was the animal world known 

 to Linnaeus. It is true that a species of kangaroo from one of 

 the islaads of the Austro-Malayan Archipelago was described as 

 long ago as 17 14 by De Bruijn, who saw it alive at the house of 

 the Dutch governor of Batavia, and that Captain Cook and Sir 

 Joseph Banks saw and killed kangaroos on the east coast of 

 Australia in 1770, and had published figures and descriptions of 

 them in 1773, or five years before the death of Linnaeus, but 

 the work we are now considering contains no traces of know- 

 ledge of the existence of such a remarkable and now so well- 

 known animal. 



The three remaining genera of Fer^, Talpa, Sorex, and 

 Erinaceiis, contained all the known species of the present order 

 Insectivora, which now embraces many and very varied forms, 

 quite unsuspected a century ago, and to which it is probable that 

 others will be added by the time the exploration of the animal 

 products of the world is completed. 



The fourth order, Glires, has remained practically un- 

 changed to our day, although the name Rodentia has generally 

 superseded that bestowed upon it by Linnaeus. The five genera 

 of the " Systema Naturae," Hyitrix Lepus, Castor, Mus, and 

 Sciuriis, have been vastly increased, partly by subdivision and 

 partly by the discovery of new forms. Noctilio is, as before 

 mentioned, removed to the Chiroptera, but its loss is well com- 

 pensated for by Hydrocharus, the well-kno'sn Capybora, the 

 largest existing member of the group, which in the Linnaean 

 system is placed among the Belhiae, in the same genus with 

 the pigs. 



The fifth Linnaean order, Pecora, is a fairly natural group, 

 equivalent to Cuvier's Ruminantia ; but it is no longer con- 

 sidered of the value of an order, since the animals composing it 

 have now been shown to be as closely related to certain of those 

 belonging to the next order as they are to each other. The 

 first genus, Camelus, contains both the American lamas and the 

 Old World camels, the demonstration of the common origin and 

 close affinities of which has been one of the important results of 

 the recent discoveries in the palaeontology of the Western con- 

 tinent. In the next genus, Moschus, were placed the well-known 

 musk deer of the highlands of Central Asia, and two small 

 African antelopes, which have no special affinity with it. The 

 subsequent inclusion in the same genus of the small chevrotains 

 {Tragulina:), which was very natural at the time, as they agree 

 perfectly with the musk in the absence of horns and the presence 

 of large canine tusks, by which artificial characters the genus was 

 defined by Linnaeus, was one of those unfortunate associations 

 which has greatly retarded the progress of knowledge of the true 

 affinities' of the group. Judging by the popular works on 

 Zoology, it is still as difficult to apprehend that a chevrotain is 

 not a musk deer, as it is that a manati is not a cetacean ; both 

 errors of the same kind, if not quite so gross, as that of regarding 

 a whale as a fish, or a bat as a bird. The genus Cervus contains 

 six species of true deer, including the moose, reindeer, red deer, 

 fallow and roe, associated with the giraffe. 



