120 EVOLUTION AND DOGMA. 



the retina. Finally, the formation of the folds of 

 the skin, known as the iris and eyelids, provides for 

 the better protection of the eye, and is a distinct 

 advance on the somewhat clumsy method of with- 

 drawal seen in the snail. This is found in the 

 cephalopoda, such as loligo. 



" If now we study the actual development of the 

 eye of a cuttle-fish, we find that the eye, although 

 a complicated one, yet passes in its own develop- 

 ment through all the above series of stages from the 

 slight depression in the skin, through the stages of 

 the pit with large and small mouth, lens, and finally 

 eyelids, being developed." ' 



In the case of the cuttle-fish, as well as in that 

 of the lancelet, we have transitory stages paralleled 

 by permanent conditions In lower forms of life. 

 The eye of the cuttle-fish, as just stated, not only 

 gives an epitome, as it were, of the history of devel- 

 opment of the visual organ in several distinct spe- 

 cies of mollusca, but also traces out for us, according 

 to evolutionists, the gradual development of the 

 eyes of the ancestral forms from which the cuttle- 

 fish itself is descended. Each stage indicated in 

 the development of the cuttle-fish's eye, marks a 

 distinct advance on the one preceding, as each 

 stage in the development of the amphioxus exhibits 

 progress from the simple to the more complex, from 

 the less highly to the more highly organized. 



It is not, indeed, always possible to adduce such 

 remarkable examples of recapitulation as those just 



1 " Lectures on the Darwinian Theory," by Arthur Milnes 

 Marshall, pp. 106 et seq. 



