MENOBRANCHUS AND LACERTA 



covers the eggs of the lizard. The young lizard emerges 

 from the egg a fully formed lizard ; the young meno- 

 branch is not so identical with its parents, and is there- 

 fore hatched at an earlier stage and therefore again 

 sooner. It has a tadpole-like form and is a larva, the 

 definition of which term will be dealt with presently. 



Excepting for a general similarity in form, every point 

 almost in external structure, not to mention internal 

 structure, differentiates the Menobranchus from the 

 Lacerta ; and if all lizards and other reptiles showed the 

 same differences from all other amphibians there would 

 obviously be no difficulty in denning the two groups. 

 But when we go farther afield, we shall find that most 

 of the points of difference break down. To amend the 

 diagnoses we will recur to the characters used in exactly 

 the same order. While most amphibians are mostly 

 aquatic, there is one group, that of the Ccecilians, 

 which are worm-like creatures burrowing in the soil, 

 and the tree-frogs spend at least most of their time, 

 as their name denotes, upon trees and other plants, 

 while toads are mostly land dwellers. Per contra the 

 crocodiles among reptiles are aquatic, as are more en- 

 tirely so the marine turtles. Certain lizards, such as 

 the Australian Leseuer's lizard (Physignathus] spend a 

 large portion of their time in water. Plenty of other 

 examples might be urged in proof of the impossibility 

 of separating reptiles and amphibia by their aquatic or 

 terrestrial habit. Nor can diurnal or nocturnal habits 

 be utilized. Both reptiles and amphibians furnish us 

 with examples of nocturnal and diurnal creatures. 

 The soft body of the amphibian, on the other hand, is a 

 character which is very widely spread, as is the scaly 

 body of the reptile. But here again there is not an 

 absolute line of demarcation. The underground and 

 burrowing lizard Amphisbczna has a softish body, though 

 it is true that it does not possess the numerous slime 



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