Slonaker, Eye of the Mole. 



349 



When these fluids are arranged in the order of their effect 

 on the eye and based on the general averages of the dimen- 

 sions in Table i, they readily fall into the order shown in 

 Table 2. 



TABLE 2. 



From this we see that 10% nitric acid causes the greatest 

 amount of shrinking and consequent distortion ; and that 

 bichloride of mercury causes little or none. In fact the tissues 

 appear as though they had been swollen. The latter, how- 

 ever, gave very poor histological preparations and was not 

 often used. The differences in diameter may be partly due to 

 individual variation. For example, in Table i, under 

 Perenyi's fluid one sees that the equatorial diameter varies 

 from .6592 mm. to .7828 mm. and the axial diameter from 

 .7622 mm. to .8652 mm. Similar variations showing equally 

 great range are seen in the specimens hardened in 2 ^ potas- 

 sium bichromate. The total averaged equatorial diameter is 

 about .']'] mm. and the axial diameter .82 mm. This is an 

 increase of over .2 mm. in similar dimensions found at birth. 

 When these dimensions are compared with those of the 

 adult European mole as given by Kohl, we notice that the 

 common mole eye is smaller. The greatest equatorial diameter 

 which Kohl found was .9137 mm. and the greatest axial diam- 

 eter was 1.0350 mm. The smallest eye he tabulates had an 

 equatorial diameter of .6034 mm. and an axial diameter of 

 .6896 mm. I presume that in his cases the great range in size 

 is probably due, partially at least, to the action of the different 

 killing fluids used. 



-The aqueous and vitreous chambers are sometimes both 



