136 



NATURE 



{Dec. 11, 1879 



M.A. ; of the Rodentia by\V. S. Dallas ; of the Edentata 

 and Marsupialia by the Editor, and of the first two Orders 

 of Birds by R. Bowdler Sharpe. 



The ruminating animals are divided into the Bovidre, 

 the Cervidae, the Tragulidae, and the Tylopodae. A little 

 more attention to typographical details would have 

 assisted in making this division more clearly perceptible. 

 Thus the first three chapters are headed quite correctly, 

 "Artiodactyla — Ruminantia : Bovidae," while Chapter IV. 

 is headed "The Cervidae," and Chapter V. has no chief 

 heading at all, although it treats of part of the Cervidae, 

 the Tragulidae, and the Tylopodas. Such a want of uni- 

 formity is apt to be a stumbling-block to the student, 

 whose perplexity is no little increased when he finds the 

 same confusion not only in the headings of the chapters, 

 but also in the text itself. Thus, in the chapters on the 

 Edentata the author seems only to have awoke up to the 

 necessity of giving any details of the order as an order, 

 when he had just finished all he had to write about the 

 species contained in the order; and as a consequence, not 

 only is the cart put before the horse, but the account of 

 the order is far too short, and almost nothing is said as to 

 the many anatomical peculiarities characterising it. So 

 much for criticism, which we make in the interests of the 



work itself, which, if completed as begun, will doubtless 

 form not only a work of useful reference to the general 

 reader, but also will be most useful as an encyclopaedia 

 of zoology. To constitute it a complete natural history, 

 of course the other kingdoms of nature will have to be 

 also treated of. 



For the antler-less deer (Tragulidae) Mr. Garrod 

 coined the useful word " deerlets." In respect of their 

 toe-bones they seem to stand intermediate between the 

 swine and the true ruminants. Each foot in the common 

 pig possesses four toes, that corresponding to our thumb in 

 the fore-limb and to our great toe in the hind-limb being 

 absent. The bones of all the toes that are present are 

 quite separate from one another just as in man, but those 

 of the outer and inner digits in each limb are smaller than 

 those which bear the larger hoofs. In the true ruminants, 

 as is well known, these larger toes are partially fused 

 together, the bones of the two central digits forming the 

 " cannon bone," while the bones of the other toe are 

 reduced to mere splints, or disappear. In the deerlets 

 these bones are not blended at all in the fore-limbs of the 

 water-deerlet of West Africa ; in which, as in all the other 

 species, the digits two and five are perfect from end to 

 end. The want of antlers in either sex is another distin- 



Ihc Lophiomys 



guishing peculiarity. We would gladly have had more 

 details given us of this very interesting group, the scientific 

 names of the species of which are in no one instance 

 given. 



The chapters on the rodents are very well and carefully 

 written, and the classification adopted is that proposed 

 by Mr. Alston. The orderly sequence of the families in 

 this section of the work might be commended as an 

 example, and the scientific names of the species following 

 their English names, in italics, is an immense improve- 

 ment on the plan generally adopted throughout this work, 

 and as a proof that the reader will find in this section 

 new as well as interesting information, we quote the fol- 

 lowing account of perhaps the most remarkable rodent 

 known : — 



" The importance of an animal in the zoological system 

 by no means depends either upon its size or on its 

 abundance in the world ; its rank in the classification is 

 decided solely by peculiarities of organisation which dis- 

 tinguish it more or less from its fellows ; and in many 

 cases the creatures which are regarded with the most 

 interest by the naturalist are those which seem most to 

 withdraw themselves from general observation. A single 



genus, perhaps containing only one or two species, may, 

 by a singular combination of characters, be so completely 

 isolated from all the recognised allied groups that it 

 cannot be placed in any of them, and accordingly a 

 distinct family, possibly even an order, has to be estab- 

 lished for its reception. Sometimes subsequent dis- 

 coveries add to the number of species forming the group 

 thus set up, and in this way the prescience of its founder 

 is confirmed. Sometimes the group remains in its original 

 condition, leaving us, according to circumstances, to 

 regard the anomalous creatures of ■« hich it is composed 

 either as a special development of their general type, or 

 as the residue of a group which may have presented a 

 greater variety of forms at some past period of the earth's 

 history. 



" The latter is perhaps the case with the curious little 

 rodent which alone forms the present family, of which its 

 original describer, M. Alphonse Milne-Edwards, writes as 

 follows : — ' In its general aspect it somewhat resembles 

 certain opossums, and like these it is pedimanous (having 

 the hind feet hand-like) ; but these are the only analogies 

 it presents to the marsupials, and in its dental system, as 

 also in the rest of its organisation, we easily see that it 



