22 MAMMARY APPARATUS OF THE MAMMALIA 







• * 



cutis thickenings of the primary-primordia act 

 as a hindrance to the extension of the pan- 



niculus carnosus. That 

 this is so is shown by 

 the sections (Fig. 9) ; 

 for the edges of the 

 skin- muscle regularly 

 present there a charac- 

 teristic turning up, 

 already observable in 

 the preceding stage 

 (Figs. 8a and 8b). Thus 

 in the middle of the 

 W0MS%, I i Panniculus, which other. 



9 





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m ^ 



w ^ 



xr "^ 



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wise spreads uniformly 

 over the ventral side of 

 the trunk, there remains 

 an oval muscle-free area 

 — the iucubatorial area 

 'fg.^^^ % w I —in the anterolateral 

 portions of which the 

 two primary-primordia 

 are situated (in Fig. 9 

 these are indicated by 

 crosses). The causes which lead to the de- 

 pression of this incubatorial area have nothing 



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9 



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2 w 



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t/2 ^; 



P pa 



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