SQ MAMMARY APPARATUS OF THE MAMMALIA 



primordia, in the course o£ further development, 

 get gradually pressed nearer together towards 

 the middle of the abdomen. In consequence, 



Fig. 23a. 



rf-e 



V 



I 



-d 



d-9 d 







Fig. 23e. Fig. 23o. 



Figs. 23a, 23b, and 23c.— Diagrams showing the 

 Genesis of the Double Row of Nipples in the 



DiDELPHIA. (BrESSLAU. ) 



the nipple primordia of the right and left side 

 become approximated, and finally the pri- 

 mordia fi, which have shifted nearest together, 



