GECKOS, LIZARDS, AND CHAMELEONS 75 



undergo a similar amputation, for in a very short 

 time a new tail is developed. This, however, is 

 never so perfectly developed as the original 

 organ. In the first place, distinct vertebrae are 

 replaced by a simple fibrous rod ; and in the 

 second, the scales clothing the outer surface are 

 rarely of the same regular arrangement as those 

 of the stump or of the last portion. Sometimes, 

 however, the more primitive ancestral arrange- 

 ment of scales is reverted to, at others the 

 arrangement is true to type, as in the Common 

 Lizard and Slow-worm, for example. It is 

 interesting to remark that though the bony 

 skeleton of the regenerated organ is not replaced, 

 the muscles of the new growth do not differ 

 greatly from those of the old stump. The tail 

 of the "Monitor" Lizards (Faranus) differs from 

 that of their allies in that, instead of being fragile 

 and easily detachable, it is, on the contrary, of 

 unusual strength. Of great length and slender- 

 ness, it appears to be used as a whip, inflicting 

 blows of considerable severity. 



Another peculiarity of the Lizard-tribe is the 

 possession of what are known as "fat bodies." 

 These are organs of unknown function, found in 

 both sexes, extending from the inguinal region 

 forwards along the belly immediately beneath 

 the skin. They are largest during the spring- 

 time, and consist of a mass of connective tissue 

 permeated with fat, which gives them a yellowish- 

 white colour. Later in the year they become 

 greatly reduced in size, forming grey or reddish 

 flaps richly supplied with blood-vessels. 



In the great number of the species, and their 



