336 Journal of Comparative Neurology. 



diameter situated well forward on the sides of the head. They 

 lie imbedded in the muscular and fatty tissues completely be- 

 neath the skin. A small, almost circular, funnel-like depression 

 marks the position of the eye cleft. It is impossible to open 

 this cleft sufficiently to see the eye. The general external 

 appearance after the removal of the hairs is seen in Fig. i, 

 Plate XVIII. This shows the position of the eye as seen from 

 the side. It shows also the presence of a rudimentary concha. 

 Some authors have claimed that an external ear is not present 

 in the mole. It cannot be seen when the fur is on, but the 

 ring-like cartilage can be readily felt. 



The relative position of the eye to the skull is shown in 

 Figs. 2 and 3. It is readily seen that the eye is no longer con- 

 fined within the bony socket as in most mammals. It is pro- 

 tected in no way by a bony frame-work and is very closely 

 associated with the skin. In fact, in removing the skin from the 

 head unless one is especially careful, the eye is also removed. 



After the removal of the integument in front of the eye it 

 appears as a small black sphere about imm. in diameter. Gen- 

 erally a lighter area can be seen in the anterior portion ot the 

 eye which marks the extent of the cornea. In the fresh con- 

 dition the shape of the eye is almost spherical. In the 

 hardened specimens, however, the contour often varies from 

 regular to very irregular (Plate XIX). This depends largely 

 on the kind of hardening fluid used. 



Methods. 



Most of the specimens were caught alive and killed with 

 chloroform and ether. Immediately after death the eyes were 

 subjected to the various hardening fluids. In some cases the 

 eye was preserved in situ, in which case orientation was main- 

 tained by attaching a small tag to a definite part of the skin. 

 In some other cases the whole head was hardened in order to 

 show the relative position of the eye. In most cases the eye 

 was isolated from the surrounding tissue. The orientation was 

 then preserved by sticking the eye on a small piece of paper to 

 which it remained attached until it was ready to be imbedded. 



