IOO 



HARDWICKE'S SCIENCE-GOSSIP. 



among the lower Eutherians, the teats are situate on 

 the breast. In the cow, mare, ass, and others, they 

 are placed in the inguinal region, while the insecti- 

 vorous Eutheria hold an intermediate place in this 

 respect, and have their mammae extending from the 

 chest to the abdominal regions. These are the most 

 common regions, but some lemurs — these are ex- 

 ceptional — have them on the arms ; and the bats, 

 such as Pteropus and Galeopithecus, have their teats 

 in the axilla or arm-pit. Supernumerary mammae are 

 by no means rare in women. Dr. Mitchell Bruce 

 (J. Anat. and Phys. xiii. p. 245) says that out of 

 207 men he examined 9* 11 per cent, had super- 

 numerary nipples, and that out of 104 women 4'Sc>7 

 per cent, exhibited the same feature. No less than 

 sixty-five cases have come under this observer's 

 notice in three years ; and without exception these 

 were situate in the front of the trunk, around and 

 about the situation of the ordinary nipple, and were 

 more frequent on the left than on the right side. 



I may add that Humboldt, in the third volume of 

 his " Travels," has recorded a case in which, after the 

 death of the mother, an infant was sustained at the 



Fig. 44. — Section of an ovary of a human foetus at the ninth 

 month, rf, ovum in its follicle, cl, corpus luteum, cyst. 



breast of its father. Also that MM. MuratandPatissier 

 in "Diet, des Sciences Med." mention a man whose 

 mamma: were as fully developed as a woman's, and 

 this was associated with a striking atrophy in the 

 reproductive organs. And Astley Cooper has corro- 

 borated this, by a similar case which fell under his 

 own notice. 



All these cases show that they nearly always — i.e. 

 supernumerary mammae — lie in the course of that 

 remarkable anastomosis which is found not merely 

 in man but in animals : on the ventral aspect of the 

 body, going up from the external iliac by way of its 

 deep epigastric branch on the one to the internal 

 mammary artery, by its superior epigastric branch 

 on the other hand. 



Darwin, in his "Descent of Man," explains the 

 occurrence of supernumerary nipples in man thus : 

 "If we suppose that during a former prolonged 

 period male animals aided the females in nursing 

 their offspring, and that afterwards 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 in- 



active." Equally probable, Mr. Sutton says, is it 

 that every mammal at one period was hermaphroditic, 

 and the mammre persist as remnants of that condition, 

 just in the same way as the parovarium which in the 

 female is functional is represented by the efferent 

 ducts of the male gland. The reader will have 

 noticed that, in Dr. Bruce's record, the number of 

 supernumerary nipples in the male record per cent, is 

 greater than that in the females. This is explained 

 easily on the principle of correlation. In the female, 

 as functional organs, the mamma? require an increased 

 blood supply, which leads to a dwarfing of the other 

 glands. The opposite of this obtains in the male. 



To turn now to another instance, and this time 

 connected with the development of ova from the 

 ovary. We have an estimate that in the cod the roe 

 contains no less than 9,344,000 ova, in the haddock 

 and the plaice six millions. Only a small portion of 

 these ever attain the adult condition, for besides being 

 preyed upon by other fish we know that they are 

 subject to fungoid growths. The number of the tad- 

 pole-larva Of our common frog never grow into their 

 manhood. Alfred Russell Wallace has computed that 

 if we take a bird that produces ten young per annum, 

 one hundred millions in forty years will be the 

 prodigious reckoning of their increase. This is just 

 as true for mammals. Waldeyer has counted 300,000 

 ova in an ovary of the human female at birth, but as 

 this was necessarily done by sections, some of this 

 number must be cut out, because of the fact that 

 any one ovum must have appeared again in two or 

 more sections. 



So far back as 1733 the fact, that Graafian follicles, 

 corpora lutea and ova become mature at the seventh 

 month of fcetal life, was known by Valisneri ; but this 

 escaped its proper share of attention till Carus, 

 writing in 1837, and Ritchie in 1842, made the know- 

 ledge more popular. Since then many workers have 

 considered this, and among these may be mentioned 

 Waldeyer, Beigel, De Sinety, and Balfour. The 

 second named of these observers has shown conclu- 

 sively, that not only do ova come to maturity during 

 embryonic existence, but also that they undergo 

 retrogressive changes and form corpora lutea. 



Mr. Sutton has collected foetal ovaries of 

 mammals ranging in species from a monkey to a 

 kangaroo, a lemur to a sloth, a Japanese deer to a 

 cat. Among the species selected may be mentioned 

 Macacus Sinicus, Macropus major, Lemur catta, and 

 Cervits silka. And he finds that the observations of 

 Beigel cited above are true, not only of man, but 

 also of mammals outside the pale of Homo sapiens, 

 and says that there is every reason to believe that it 

 is equally true as regards those vertebrates yet again 

 who hold their standings in the forum of zoological 

 existence, external to the mammalian circle. Then 

 he thinks that this is only to be explained on the 

 grounds of an amphibian ancestry of man, which in 

 turn is evolved from a piscine condition. And then 



