Anatomy and Physiology of the Mammary Gland. 87 



several illustrations, showing that the different sets of tubes, 

 when filled with various coloured injections, have in no way 

 commingled with each other. In all animals, therefore, in which 

 such a conformation exists, partial destruction of a gland can 

 occur, and the unaffected portions still continue their secretinii- 

 functions. The accompanying woodcut, Fig. 2, will exemplify 

 this peculiarity ; the different sets of tubes being marked con- 



/ \'^ ^ i ^« -){ Sy. 







\ 



Y 



/ \ 



■o 



Illustrates the lactiferous tubes, as arranged in those animals which 

 <Io not possess proper millc reservoirs, and in which several distinct 

 ducts pass tlirouuh the teats to external outlets. The numerals, 1, 2, 

 .'3, 4, 5, 6, 7, 8, 9, indicate separate sets of tubes in the substance of tlie 

 mammae, which are dilated here and there, and curved in various 

 directions for tiie retention of tlie milk. (After Sir A. Cooper.) 



