REPTILES 445 



'Avancez,' I said, 'go ahead; I'm certain that's a snake's nest.' 

 Lifting up the straw most carefully, I was delighted to find first one, 

 then two, then a dozen eggs. The squire and I then proceeded 

 to dissect out the nest with our pocket-knives and a dung-fork most 

 carefully. Snakes' eggs are not quite so large as a blackbird's; 

 they are round at both ends like a sugar-plum. They have no 

 hard shell like a hen's egg, but the shell is composed of a soft 

 elastic substance, like thin wash-leather. Some eggs were lying 

 quite separate. The greater part were, however, stuck firmly 

 together, so tightly that it was almost impossible to tear them 

 apart without breaking the skin. The eggs were not held by a 

 ligature, but appeared pasted together by some strong adhesive 

 gum, end on end. . . . The appearance of the eggs in this dung- 

 heap, just as the parent snake or snakes had placed them, was so 

 striking, that a gentleman, well-known for his artistic talent, took 

 a sketch of the eggs and the nest. When the sketch was finished, 

 I proceeded to examine the eggs more closely; there were sixty- 

 four. I do not know from experience how many eggs the 

 common snake lays, but I should say from twelve to twenty. It 

 is, therefore, possible, even probable, that more than one snake 

 had chosen the spot on the dung-hill to deposit their eggs. . . . 

 The temperature of the spot where the eggs were deposited in the 

 dung-heap was about 84 degrees in the sun, and the nest was 

 buried about 18 inches deep on the southern aspect, as though the 

 mother snake knew that that was the best place for the eggs." 

 The unhatched snake is provided with a small "egg-tooth " on the 

 tip of its snout, which helps it to make its way into the world. 



Parental affection is rarely exhibited by snakes, but the female 

 Python coils her body round her batch of eggs by way of protec- 

 tion. Some few species, such as Vipers, including our native 

 Adder (Pe/ias berus), are viviparous. So also are marine snakes, 

 which come to land for the purpose of producing their young. 



Lizards (Lacertilia). — Most of these are oviparous, and 

 deposit their hard or soft-shelled eggs after the fashion of Snakes. 

 Here too, the young animal possesses a sharp "egg-tooth" (fig. 

 968) on the tip of its upper jaw, and this is best developed in 

 cases where the egg-shells are hard and calcareous. The Common 

 Iguana {Igtiana tuberculata) of tropical America digs out a deep 

 burrow on a sloping bank for the reception of her eggs, the Eyed 

 Lizard {Lacerta ocellata) commonly selects a hollow tree for the 



