218 THE DESCENT OF MAN 



in tlieir abdominal pouches, hatch them, and afterward, as 

 some believe, nourish the young;'" that certain other male 

 fishes hatch the eggs within their mouths or branchial cavi- 

 ties ; that certain male toads take the chaplets of eggs from 

 the females, and wind them round their own thighs, keeping 

 them there until the tadpoles are born; that certain male 

 birds undertake the whole duty of incubation, and that 

 male pigeons, as well as the females, feed their nestlings 

 with a secretion from their crops. But the above sugges- 

 tion first occurred to me from the mammary glands of male 

 mammals being so much more perfectly developed than the 

 rudiments of the other accessory reproductive parts, which 

 are found in the one sex though proper to the other. The 

 mammary glands and nipples, as they exist in male mam- 

 mals, can indeed hardly be called rudimentary; they are 

 merely not fully developed, and not functionally active. 

 They are sympathetically affected under the influence of 

 certain diseases, like the same organs in the female. They 

 often secrete a few drops of milk at birth and at puberty ; 

 this latter fact occurred in the curious case, before referred 

 to, where a young man possessed two pairs of mammas. In 

 man and some other male mammals these organs have been 

 known occasionally to become so well developed during 

 maturity as to yield a fair supply of milk. Now if we 

 suppose that during a former prolonged period male mam- 

 mals aided the females in nursing their offspring," and that 

 afterward from some cause (as from the production of a 

 smaller number of young) the males ceased to give this 

 aid, disuse of the organs during maturity would lead to 

 their becoming inactive; and from two well-known princi- 



*" Mr. Lookwood believes (as quoted in "Quart. Journal of Science," April, 

 1868, p. 269), from what he has observed of the development of Hippocampus, 

 that the walls of the abdominal pouch of the male in some way afford nourish- 

 ment. On male fishes hatching the ova in their mouths, see a very interesting 

 paper by I^rof. Wyman, in "Proc. Boston Soc. of Nat. Hist.," Sept. 15, 1857; 

 also Prof. Turner, in "Journal of Anat. and Phys.," Nov. 1, 1866, p. 18. 

 Dr. Giinther has likewise described similar cases. 



" Mdlle. C. Royer has suggested a similar view in her "Origine d« 

 I'Homme," etc, 1S10. 



