22 BRITISH SERPENTS. 



varies accordino- to the amount of moisture absorbed 



o 



and to the time of development, but they are gen- 

 erally about an inch long when found, and the bulk 

 of a pigeon's egg. 



The eggs are laid in the late spring or early summer, 

 and having selected the spot for their deposition, the 

 female apparently cares no more about the future of 

 her offspring. The spot selected more often than not 

 takes the form of a heap of manure (which offers both 

 warmth and moisture), or any convenient collection of 

 rubbish. But bundles of the eggs may be found in all 

 sorts of places — in fagots, in old walls, or any warm 

 moist vegetable material. The separate eggs adhere 

 together by means of a glutinous secretion deposited 

 with them, and which causes them to adhere in strings 

 even when the young have left the eggs, and the latter 

 are quite dry and brittle. The covering of the embryo 

 is not shell but a tough leathery membrane, through 

 which moisture can penetrate. The period of develop- 

 ment varies somewhat with the heat and moisture to 

 which the eggs are exposed, but is generally about 

 eight weeks after the eggs are extruded. This is not 

 the whole length of the period of development, which 

 has already reached a certain stage when the eggs are 

 deposited. " The embryo at the time of hatching is 

 provided with a temporary horny tooth on the snout, 

 to cut through the eggshell." ^ 



Anatomy. — Without going into any great detail 



1 Packard. 



