238 Notes, iv. 10. 



17. Cf. iv. 12, Note 10. 



18. "L'homme porte les aliments i la bouclie au moyen du membra siiperieur. Les 

 diverses pieces dont se compose ce membre sont disposees de telle sorte, que leur mouve- 

 ment de flexion dirige naturellement la main vers la bouche " (Beclard, F/iys. p. 42). 



19. Horses, when fighting together, use their fore-legs for striking, much more than 

 they do their hind-legs for kicking backwards. Cf. Darwin, Exp. of Emot. p. 112. 

 The main statement in the text is, however, correct. The anterior limbs in Ungulata 

 are quite useless for prehension, and only subserve locomotion. Hence the absence of 

 clavicles. Whereas in Unguiculate animals, speaking generally, the anterior limbs serve 

 more or less as prehensile organs, and are furnished as a rule with more or less perfect 

 clavicles. 



20. Analogous is here used in the modem sense, i.e. having similar functions, and not 

 as equivalent to homologous. For A. has already said that the fore-limbs of quadrupeds 

 correspond anatomically to the arms of man. 



21. In Canidse and Felidae, from which A.'s examples are taken, there are only four 

 toes to the hind-foot, while the fore-feet have each five, as in most Unguiculata. 

 The smaller quadrupeds, that are described as having five hind-toes and as creeping or 

 even running over -head, are such animals as rats, squirrels, moles, martens, weasels. 

 It is, however, not only small quadrupeds and creepers that have five hind-toes ; for the 

 same is the case with elephants and bears. 



22. Cf. ii. 16, Note 5. " Is not this one of the most admirable things in the works 

 of nature, that she should take some part that has been developed in an animal for some 

 special function, and utilise it for some additional office ? " {Galen, De U. part. vii. 22). 

 Cf. iii. I, Note 12. 



23. The upper or true ribs which are united to the sternum, in opposition to the 

 false ribs below. Thus there is firmness given to the mammae by the firm substratum. 



24. As the arms are not used for locomotion, the mammas are not in the way, and 

 so there is no disadvantage in there being two of them ; otherwise they would be made 

 to form a single mass. 



25. Elsewhere (//. A. ii. 8, 4), apes, as well as man, are excepted. Pectoral mamm^ 

 are by no means confined, however, to man and apes. In bats, for instance, the two 

 mammae are pectoral ; so also in elephants, as indeed is presently mentioned. 



26. The homed animals which produce few at a birth and have only two mammae are 

 sheep and goats. For in other horned animals, e.g. the cow, there are four, as A. 

 elsewhere {H. A. ii. i, 40) mentions. Even in sheep and goats there are really four ; 

 but two of these are usually rudimentary. The Solidungula have, as correctly stated, 

 only two mammae and these inguinal. 



There is, as stated in the text, a very close correspondence between the number of 

 mammae and the number of young produced at a time. The larger uniparous mammals 

 have but two mammae, e.g. elephant, rhinoceros, hippopotamus, horse, etc. The 

 Ruminantia often produce two, and some of the larger Camivora two or more, at a birth ; 

 and these have as a rule four mammae. Most smaller Camivora, Insectivora, Rodentia 

 are multiparous, and also have numerous mammae. Thus the cat has three to six young 

 at a time and eight mammae. The dog has litters of four to nine, and seven to ten 

 mammae. The hedgehog has six to seven young and ten mammas. Rabbits, hares, 

 marmots, black rats, all multiparous, have each ten or more mammae.- So far then A. 's 

 statement is correct. But he seems to fancy that there is also some relation between the 

 number of mammas and the number of toes. Of course no such direct relation exists. 

 Still it is true that the one-toed Solipedes have but two mammae ; the cloven-hoofed 



