NATURE 



[Nov. 4, 1875 



racters indicated by the presence or absence of the carina, 

 it is almost impossible to recognise in the sternum any 

 of those distinguishing features which may be stated in a 

 single word, or may be incorporated as a definition in any 

 tabular arrangement. The sternums of most birds, even 

 those which are most peculiar, must be considered in their 

 entirety, and a complete description is necessary for their 

 differentiation." We would feel disposed to go even 

 further than this, and to say that in the sternum there are 

 characters from which, with a little extraneous assistance, 

 more considerable generalisations may be arrived at. It 

 is true that in the passerine Ptcroptoc]iiis the posterior 

 margin is doubly notched on either side, but in how 

 different a manner from that in the piciform birds and 

 owls ! What more than the sternum proves the closeness 

 of the relationship between the Toucans, Woodpeckers, 

 andCapitoes, also between the Swifts and the Humming 

 Birds, as well as the small kinship between the galli- 

 naceous birds and the Sand Grouse ? On the other hand, 

 the sternum does not aid us much in the determination 

 of more distant relationships, such as those of families 

 one to the other. From it alone we should not feel 

 justified in placing the Tinamous near the Apteryx, nor 

 the Stormy Petrels near the Fulmars. 



In the Bulletin dc la Societi Philoinathiqiie and in the 

 "Journal de Zoologie Dr. Alix has published his dissec- 

 tions of the Rhea and of a Tinamou {Nothura major). 

 His myological investigations are based on the descrip- 

 tions given by Vic d'Azyr and Meckel. Following the 

 latter of these, he mentions that in the Cormorant the 

 ambiens muscle {accessolre iliaque du Jlc'chtsseur per/or^) 

 is absent, which is decidedly not the case in the common 

 species {Phalacrocorax carbo). With reference to this 

 bird, the accessory femoro-caudal is said to be repre- 

 sented by an aponeurotic band, which we have failed to 

 detect ; and the same remark applies to the muscle itself 

 in the Heron {Ardea ctnercd)^ in which it is also said to 

 be developed ; from which we may infer that the author 

 has evidently not clearly recognised the characters which 

 distingui sh this fleshy fasciculus from the obturator exter- 

 nus {carre) ; and that such is the case is further proved 

 by his statement that the latter named muscle is enormous 

 in the ostrich, in which it is in reality very small, being 

 almost hidden by the former. 



The flexor tendons of the toes are specially dwelt on. 

 The flexor perforatus digitorum is shown to present pecu- 

 liarities sufficiently important to deserve special names. 

 This muscle in birds is not a single one, but is formed of 

 a superficial and a deep group ; the latter having two 

 separate origins, an internal and an external, of which the 

 relative proportionate bulks vary. Those birds in which 

 the outer head is the larger are termed edotnyensj those 

 with a larger internal head, entomyens j and those with 

 equal heads, homceomyens. " The palimpeds, the longi- 

 rostral and pressirostral Waders, the Flamingoes, the 

 Storks, the Tinamous, the struthious birds and the Parrots, 

 are entomyen ; the Herons, the Rails, the galling. Pigeons 

 and passeres, are homoeomyen ; whilst the diurnal and 

 nocturnal birds of prey are ectomyen." The deep flexors 

 are said not to offer such remarkable differences as those 

 just referred to, but as none of their most striking pecu- 

 liarities are mentioned, we presume that the author is 

 unacquainted with them. The long flexor tendon to the 



hind toe, we arc told, is absent in the swan ; it may be 

 so in Cyj^nus olor, such is certainly not the case in 

 C. nigricollis. 



The last section of the work is almost entirely devoted 

 to the flight of birds, this subject being viewed from a 

 theoretical standpoint only. It is demonstrated in a 

 fairly conclusive manner that the assumption of Borelli, 

 in Avhich the wing is considered to strike directly down- 

 wards and to turn backwards simply on account of the 

 yieldingness of its posterior margin, is insufficient to 

 explain the different movements observed ; at the same 

 time that it is opposed to the results arrived at from a 

 study of the shape of the articular surfaces of the 

 shoulder, and the arrangement of the fibres of the 

 muscles acting on that joint. This, we think, is the 

 tendency of modern investigation, notwithstanding the 

 support, by M. Marey, of the opposite view. The results 

 of the elaborate investigalions of this latter able physi- 

 ologist are as easily explained upon the one assumption 

 as the other, perhaps better on the anti-BorelHan theory, 

 which no doubt is not required to account for the move- 

 ments of the wings in the much less intricate problem of 

 insect flight. 



The following are Dr. Alix's propositions on this sub- 

 ject : — " First. The wing in the down-stroke begins by 

 moving forward to attain its basis of support ; after which 

 it strikes briskly from above downwards, and at the same 

 time from before backwards, as a result of which the bird 

 is projected forwards. Second. At the moment at which the 

 wing commences to descend, its lower surface looks for- 

 wards ; but as it descends, this surface gradually turns to 

 look directly downwards, and ultimately more and m.ore 

 backwards. Third. During the ascent of the wing, it 

 moves upward and forward, its inferior surface at the 

 same time looking forward." The nearly complete agree- 

 ment of these observations with the results of M. Marey's 

 previously published experiments is worthy of note, con- 

 sidering the differences in the starting-points of the two; 

 authors. The question of avian locomotion, as it now 

 stands, is therefore not so much as to what are the 

 positions of the wing during the different parts of the 

 stroke, but as to whether the variations in the direction of 

 its plane depend for their origin on the movements im- 

 parted to the humerus by the muscles acting on the 

 shoulder, or on the influence of the resisting air upon a 

 vertically moving plane which is more yielding behind 

 than in front. This question requires further elucidation, 

 though, as we have just remarked, we think, with Dr^ 

 Alix, that the balance of evidence is considerably it 

 favour of the former view. 



In conclusion, we strongly recommend this complete 

 and able exposition of the locomotor apparatus of birds to 

 all students both of physiology as well as of zoology. 



" THE ABODE OF SNOIV" 



The Abode of Snow. Observations on a Journey from 



Chinese Tibet to the Indian Caucasus, through the 



upper valleys of the Himalayas. By Andrew Wilson. 



(Edinburgh and London : W. Blackwood and Co., 



1875.) 



LAST week we noticed Mr. Drew's almost exhaustive 

 work on Jummoo and Kashmir ; Mr. Wilson's work 

 is to a large extent concerned jwith _the same region, as 



