ATAVISM. 171 



had an areola of pigmented skin ; when removed, 

 and the parts examined microscopically, glandular 

 tissue was found beneath it. 



The most frequent situation on the exterior of the 

 body in which to find aberrant mammae is the arm-pit ; 

 here they appear as glandular masses, communicating 

 with the free surface of the skin by means of nipple- 

 less pores, and in parturient women furnish milk and 

 colostrum. Champneys has particularly investigated 

 this form of mammae, and finds that they are of frequent 

 occurrence. Axillary mammae with nipples have been 

 recorded by several reliable observers. 



The tendency of protected cutaneous surfaces to 

 become glandular is a matter of great interest, not only 

 in connection with aberrant mammae, for it serves to 

 explain the abundance of teats lodged within the pouch 

 of opossums. 



It is a noteworthy fact that cutaneous and mucous 

 recesses are as a rule richly supplied with glands. Take, 

 for instance, the large glands besetting the ocular aspect 

 of the eyelids, the crowd of glands lodged in the arm- 

 pit, in the external ear-passage which secrete ear-wax, 

 and in many situations which readily suggest them- 

 selves to anatomists. As far as. I have looked into the 

 matter, no one has suggested any useful purpose served 

 by glands in these situations worthy a moment's 

 reflection. 



The consideration of cutaneous recesses leads us to 

 deal with the remarkable pouch of marsupials, which is 

 neatly described as the bag of the opossum by Paley in 

 his " Natural Theology " : " A false skin under the 



