Owen's mammary pouches 33 



What, then, are Owen's mammary pouches 

 which have hitherto played so great a part in 

 the speculations regarding the evolution of the 

 mammary apparatus ? They certainly do not 

 occur in the stages we have so far considered, 

 and, I may add, they do not appear at any 

 later stage. In a word, the mammary pouches 

 do not exist, and Owen's statements on the 

 subject are completely wrong. 



Owen's mistake is to be explained by the 

 fact that the abdominal wall of the female 

 Echidna he examined had been divided longi- 

 tudinally with a view to studying the genital 

 apparatus before coming into his hands, as he 

 himself states. He was thus not in a position 

 to recognize the incubatorium, cut up as it 

 was, as a single formation. The unfortunate 

 part is that Owen did not give drawings of the 

 specimen as he saw it, but figured what he 

 supposed to be the true relations (Fig. 3). 



The fact that these illustrations of Owen's 

 could be looked upon for forty years as 

 valuable evidence for the existence of the 

 mammary pouches, the appertaining text being 

 wholly ignored, forms, as it seems to me, an 

 interesting chapter in the history of scientific 

 3 



