42 Prof. Car us on. the relative Proportions of the Eye. 



extent, expresses rather something spiritual or celestial. The 

 pious painters of the old Italian and German schools had a clear 

 idea of this proportion, and in their representations of eyes of vir- 

 gins, angels, Christ, and saints, it may be seen that the pupil and 

 iris are smaller in relation to the sclerotic, than they are in well 

 formed ordinary eyes. From this it may be presumed, that the 

 eye of the foetus will equally present modifications in the pro- 

 portion of the parts of which it is composed. The results which 

 M. Carus has obtained, in consequence of accurate measure- 

 ments, are the following : 



years, 



It is seen from this, that the proportion of the breadth of the 



iris to that of the gl6be of the eye, as well as that of the iris to 



the axis of the eye-ball, increases with age. The following is 



another table, which presents some points of comparison with 



the eye of animals : 



Relations of the breadth Relation of the breadth 



Animal. of the iris to that of the of the iris to the axis 



globe of the eye. of the globe of the eye. 



Pike *, . . 8.5 : 10.5 = 1 : If J 8.5 : 8.5 = 1 : 1 



Crocodile, ,5.0 : 7.5 = 1 : If J 5.0 : 6.5 = 1 : IJg 



Golden eagle, 7.5 : 16.0 = 1 : 2^ ? 7.5 : 14.6 = 1 : 1|J 



Chamois, . 10.5 : 14.0 = 1 : l//y 10.5 : 12.8 = 1 : 1//^, 



There results from all this, that the eye of the foetus only as- 

 sumes by degrees the proportions that obtain in the eye of the 

 adult ; and that the smallness of the iris, in proportion to the 



* Brochet, Esox iucius, Linn. 



