294 FROGS, TOADS, AND NEWTS [CH. VIII 



in the position of the anterior abdominal vein. This 

 vessel in toads lies dorsal to the muscles forming the 

 ventral wall of the abdomen, whereas in frogs it runs 

 in the substance of the muscles themselves. The toad, 

 like the frog, periodically sloughs the outer layer of the 

 skin ; the process takes place about five times each season ; 

 the cast-off layer is swallowed. 



The breeding season of the toad is rather later in the 

 year than that of the frog. The spawn, instead of being 

 deposited in masses, is in ropes, three or four feet in 

 length, each rope consists of a double row of eggs arranged 

 alternately on either side. The mucous envelopes of the 

 eggs are rather more transparent than in frogs' spawn. 

 The hind legs of the female are employed in thrusting the 

 spawn-rope backward away from the body as the eggs are 

 being laid. The general course of development does not 

 differ in any important particular from that already de- 

 scribed : the young tadpoles are, however, rather smaller 

 and of a more intense black colour. 



Toads are said to attain a very great age. I am 

 not aware of any exact trustworthy records of the length 

 of life, but have no hesitation in asserting that the reports 

 of toads found entombed in solid chalk and other rocks 

 have originated in imperfect observation of the facts. 

 The absence of ribs makes it possible for a large toad 

 to squeeze itself through a very narrow crevice. At the 

 approach of winter the animals retreat into deep holes 

 or other sheltered spots, and become torpid through the 

 cold weather. 



(3) The Natterjack Toad, Bufo calamita, is of rarer 



