EPIDERMAL APPENDAGES, z^l 



They reminded one of Darwin's words, and though my style 

 of talking to my pets was such as to suit lizard comprehen- 

 sion solely, I did sometimes warn them in plain English. ' If 

 you don't give your legs sufficient exercise, they will dwindle 

 away by and by, and your descendants will have no hind 

 legs at all ! ' 



After thus moralizing to the unheeding lacertines, it was 

 with secret gratification that one heard Professor Huxley, in 

 his Lecture on 'Snakes 'at the London Institution, Dec. i, 

 1879, say — as nearly as I can remember — 'In evolution or a 

 gradual change, the lizard found it profitable to lose its legs 

 and become a snake ; all modifications are an improvement 

 to the creature, putting it in a better condition.' In this 

 better condition,' therefore, does the slow-worm find itself, 

 when it glides noiselessly, and almost without stirring a blade 

 of grass, into its burrow. In other lizards one may some- 

 times observe that the hiJid legs are most used in scratching 

 and pushing the earth away. Thus, in the constricting 

 snakes — these descendants of some pre-ophidian lizards — 

 the unused limbs have become obsolete ; and the spine, 

 gaining strength with increased action, has at length become 

 to the constrictors their hands, feet, arms, and legs, and 

 endowed with those wondrous capabilities which were de- 

 scribed in chap. xii. 



To return to the integument. As one of its developments, 

 the hood of the cobra may be included in this chapter, the 

 skin here exhibiting its extensile or expansive construction. 

 It is the longer ribs, about twenty pairs nearest the head 

 (see p. 33), which really do form the hood. These anterior 

 ribs, gradually increasing in length and decreasing again, 



