690 TOUNG SPECIMEN OF ORNITHOREYSCHUS ANATINUS. 



muzzle of the Ornithorhynchus. As matter of fact the skin of 

 the snout of both young and adult Ornithorhynchi possesses a 

 stratum corneum which is only moderately thick, which is as soft 

 and flexible as epidermis elsewhei'e, whose cell-outlines and nuclei 

 remain distinct right to the surface and which is traversed by 

 innumerable sweat-ducts and the delicate tactile rod-organs. In 

 view of these characters and in the absence of any special physico- 

 chemical transformation of the tissue, as distinct from what 

 occurs in the general epidermis, e.g., of a dog's nose or of the 

 human hand or foot, I can see no purpose or meaning in retaining 

 the old and thoroughly misleading idea of the " horny " character 

 of the " beak " of the " duck-billed platypus." 



The special histological characters of the caruncle will be treated 

 of in a future publication. 



EXPLANATION OF PLATE. 



Fig. L — "Mammary foetus" of Ornithorhynchus anatinus. Life size. 

 Ventral aspect. 



Fig. 2. — Tlie same. Life size. Lateral aspect. 



Fig. 3. — The same. x 3 diams. Ventro-lateral aspect (right). 



