INCUBATORIAL AREA IN ECHIDNA 



21 



examination, these priraordia now appear dis- 

 tinctly as circumscribed, oval, bare areas in 

 the anterolateral corners of the hair- clad incu- 

 batorial area, as may be seen in Fig. 11a (Z)r, 

 Z)e), representing the appearance of a stained 



Fig. 11a. Fig. 11b. 



Figs. 11a and 11b. — Echidna: Dkawings of the 

 Mammary Areas of Two Pouch- Young. Semon's 

 Stages 50 and 51. 



Dr, De, Gland areas. 



and cleared preparation of the complete incuba- 

 torial area. 



A little later, in Stages 50 and 51 of Semon, 

 the development of hairs begins within the 

 primary -primordia also, and, indeed, all at once, 

 and with a vigour never . shown elsewhere in 

 the skin (Fig. lis, Dr, De). The number of 



