18 THE STRUCTURE OF MAN 
soon after birth and at the time of puberty, may produce milk 
(so-called “witch’s milk”) from more or less swollen breasts.’ 
Milk has also certainly been obtained from male goats and from 
castrated rams, and this has been found on chemical analysis to 
be even richer in caseine than ordinary milk. 
[In this connection it is interesting to note that Dobson has 
called attention (British Museum Catalogue of the Chiroptera, 
Lond., 1878, pp. 79 and 83) to the great development of the — 
teats in the males of certain frugivorous Bats. He points out 
that while many Bats are known to bring forth two young at a 
birth, he has never found a mother with more than one clinging 
_ to her body; and he inclines to the belief that in such cases the | 
male may relieve the female of the charge of one of the young 
ones (as the weight of two might render flight difficult or 
impossible). He suggests that “instances of the male performing 
the office of nurse are probably not uncommon among Bats.” ] 
The following results on the subject of supernumerary breasts 
and teats were obtained by Leichtenstern, from the study of 
extensive data :— 
Cases of polythely, with or without polymasty, were observed 
with almost equal frequency in the two sexes. On an average, 
one case may be expected in every 500 individuals. 
In 91 per cent the accessory glands and teats were developed 
on the anterior side of the thorax, and in by far the greater 
number (94 per cent of these) they were found below (caudad of) 
the normal teats, in a convergent disposition. 
The following is a table showing the position occupied by 
the accessory mammille in the 105 cases recorded by Leichten- 
sbenn 
On the anterior side of the thorax : J 96 cases 
In the axilla . : : Digs 
On the back : ; Dic. 
Above the acromion . ° - : : 1 case . 
On the outer side of the hip . ; Lie 
Rudimentary breasts occurring above (cephalad of) the normal 
ones are of rare occurrence (3 per cent), and these (Fig. 13, m’) 
always lie outside the normal mammary line in the direction 
of the axilla) Want of symmetry, especially on the left side, is 
common in all cases of rudimentary teats or mammary areas, in 
whatever part of the body they occur. The rarest condition 
1 Decided swelling of the breasts is sometimes found in youths of from twenty to 
twenty-one years of age, in cases of retarded puberty (Ammon). 
