42 BLIND VERTEBRATES AND THEIR EYES. 



THE BLIND REPTILES. 



AMPHISByENA PUNCTATA. 1 



Amphisbcena punctata (Bell) is a blind, legless lizard which burrows in the ground. 

 It is common in Cuba, to which place it is restricted. How deep it burrows can 

 not be stated, but it is often turned up by the plow. The specimens obtained 

 ranged from 103 to 245 mm. in length. The head is short, hard and pointed, and 

 the tip of the upper jaw projects slightly beyond the tip of the lower. In shape, 

 arrangement of the dermal plates, and color of the ventral surface of the body it 

 closely resembles an earthworm. The dorsal surface is flesh-color with small 

 brown spots. The tail is short and flattened dorso-ventrally. In a specimen 245 

 mm. in length, there were 225 annuli on the dorsal side, 202 on the ventral, and 15 

 on the tail. In this specimen the tail was one-thirteenth and the head one-thirty- 

 fifth the length of the body. 



METHODS. 



The lizards were put alive into formalin. They were afterwards put into alco- 

 hol. For decalcification, the heads were placed in 5 per cent nitric acid from 20 

 to 30 days. A shorter period did not give satisfactory results. Some heads were 

 embedded in paraffin and others in paraffin and celloidin. In using the latter 

 method the head was embedded in celloidin in the usual manner and hardened in 

 chloroform. From chloroform the block was transferred to soft paraffin for 24 

 hours and thence to hard paraffin for 24 hours, after which it was embedded in 

 paraffin. The best results were obtained from those embedded in paraffin and 

 celloidin. Several methods of staining were used ; iron hsematoxylin with eosin as 

 a counter stain gave the best results. The more modern methods of treating the 

 retina with silver could not be applied for lack of fresh specimens. On account 

 of the extreme toughness of the cuticle it was impossible to get complete series of 

 sections. For comparison the eye of Anolis carolinensis has been examined. 



GENERAL ACCOUNT OF THE EYE. 



The eye of Amphisbcena appears indistinctly as a small 

 black spot beneath the ocular plate (fig. 12). In a specimen 

 225 mm. in length, the eye is 352 fx. beneath the surface, 420 jjl 

 in width, and 360 /x in depth. The conjunctival sac is 116 jx 

 in diameter. The conjunctiva is very thin over the cornea, 

 fig. 12. Head of Amphisbcena but measures 4 m in thickness over the anterior part of the sac. 



punctata (Bell) showing Loca- . . . 1 



tion and Relative size of Eye. The dermis and epidermis have the same structure over 

 the eye as over the regions near by. This corresponds with 

 what Eigenmann ("The Eyes of Rhineura floridana," 1902) found in Rhineura, 

 although the eye of Rhineura is a much more degenerate organ than the eye of 

 Amphisbcena, but to what extent the eye is degenerated from a more elaborate 

 structure can not be stated. Few organs are stationary, and this one is probably 

 still in process of reduction. The writer has been unable to obtain the young, 

 and there is no means of finding out from the adult whether the eye is degenerat- 



1 By Fernandus Payne. See Biol. Bull. XI. 60, 1906. 



