TEGUMENTAL ORGANS 19 



(only one case being known) is that in which a supernumerary 

 teat occurs in the same horizontal plane with the normal teats, 

 either at or near the median line. 



Hyrtl put forward the view that the greater development of 

 the left breast is due to the habit of feeding the child from that, 

 in order to leave the right arm free. Leichtenstern opposes this, 

 but does not furnish any satisfactory explanation of the fact. 1 



FIG. 13. EXAMPLE OF POLYMASTY. (After Hansemann.) 



The position of the supernumerary breast (m") is superior and lateral to that of 



the normal (?') The left accessory gland has a second teat (mf"). 



Kudimentary mammary organs were never found by Leichten- 

 stern below the costal ridge or in the inguinal region. 



In the Dog the normal number of teats varies from seven to 

 ten, and Cuvier's dictum that the numerical variation in breasts 

 is greatest where they are most numerous is thus confirmed. 



Towards the end of the last century, Professor Socin of Basel, 

 and subsequently the Medical Faculty of the University of 

 Tubingen, were consulted by a lady with four breasts, as to 

 whether she could marry without incurring the danger of having 

 twins at every birth. The authorities decided that polymasty 

 did not imply predisposition to bear twins, and the result proved 

 the correctness of this opinion. Among seventy women with 

 polymasty, twins are known to have been born in only three cases. 



1 [It may be remarked here that the young " vervet " (Cercopiihecus lalandii) has 

 been recently observed to suck both teats at once (Proc. Zool. Soc., Loud. 1893, 

 p. 615).] 



