298 



WHALES 



Figure lys. Sketch of the 

 skin of a Porpoise. E = 

 epidermis; D = dermis 

 with venous retia; B = 

 blubber; A = artery sur- 

 rounded with venules ( V) ; 

 left (white) : a large 

 efferent vein; P = dermal 

 papilla reaching almost to 

 the top of the epidermis 

 where it is broadened. Tfie 

 papilla contains arterioles 

 surrounded with a number 

 of venules (see Fig. 1^3), 

 and capillaries at its tip. 

 (Parry, ig4g.) 



According to Van Utrecht, the blood is returned by a number of veins 

 which completely surround the tiny arterioles of the papillae (Fig. 173) 

 in much the same way as some larger arteries of Cetaceans are surrounded 

 with veins (see Chapter 5). As a result of this arrangement, which, by the 

 way, is also found in the papillae of the gum (see Chapter 10), as much 



Figure I/3. Cross-section through a dermal 

 papilla in the epidermis of a porpoise. The 

 large vessel in the centre is an arteriole sur- 

 rounded with venules (see Figure gy). 

 (Prepared by W. L. van Utrecht.) 



