120 REPTILES. 



oval instead of circular, and convex instead of con- 

 cave ; and each contains a distinct oval and granular 

 nucleus. 



REPTILES. In reptiles, as the frog, toad, or water- 

 lizard (Triton) , the bone-corpuscles or lacunae are 

 larger and more numerous than in either of the former 

 classes ; and the blood- corpuscles (PL IX. fig. 3) are 

 comparatively very large, oval, rather concave, and 

 contain a large granular nucleus. 



The smooth water-newt or triton, properly called 

 Lissotriton punctdtus, is a very interesting animal in 

 a microscopic point of view. It may be found in most 

 ponds ; and if several are removed in a net, and kept 

 in a large glass jar, with water-plants, they will live 

 for a long period. In the spring or early summer 

 they will deposit their eggs upon the aquatic plants, 

 generally on the under surface of a leaf, which they 

 bend downwards, so as to protect them. The eggs or 

 ova, are about half the size of a pea, and consist of a 

 sac containing a transparent liquid, with a yellowish 

 globule within. After a time these eggs will hatch, 

 and the larvae or young newts must be removed from 

 the water, otherwise the parents will devour them. 



If one of these larvae, which resemble little fish in 

 appearance, be placed with a little water in the ' ' live- 

 box/ 7 and the cap be very gently pressed down, so as 

 to fix the body of the animal, the circulation of the 

 blood may be very beautifully seen in either the 

 fringe-like gills, which are placed on each side of 

 the neck, or in the tail, a low power being used; 

 at the same time the beautiful stellate pigment- 

 cells of the skin will be observed. The struc- 

 ture of the rudimentary spinal column, which runs 

 down the middle of the back, and consists of simple 

 large cartilage-cells, may also be made out, when the 

 animal is dead, by a little dissection with the aid of 

 needles. 



FISHES. In the fourth class of vertebrate animals, 



