Essays on Life 



sequent offspring, in spite of the fact that we 

 can rarely find the effect in any one genera- 

 tion, or even in several, sufficiently marked to 

 arrest our attention. 



I will now show that offspring can be, and 

 not very infrequently is, affected by occur- 

 rences that have produced a deep impression 

 on the parent organism the effect produced 

 on the offspring being such as leaves no doubt 

 that it is to be connected with the impression 

 produced on the parent. Having thus estab- 

 lished the general proposition, I will proceed 

 to the more particular one that habits, in- 

 volving use and disuse of special organs, with 



them, and have their eyes accordingly placed on either side of 

 their head. Some fishes, however, have their abode near coasts 

 on submarine banks and inclinations, and are thus forced to 

 flatten themselves as much as possible in order to get as near 

 as they can to the shore. In this situation they receive more 

 light from above than from below, and find it necessary to pay 

 attention to whatever happens to be above them ; this need has 

 involved the displacement of their eyes, which now take the 

 remarkable position which we observe in the case of soles, tur- 

 bots, plaice, &c. The transfer of position is not even yet com- 

 plete in the case of these fishes, and the eyes are not, therefore, 

 symmetrically placed ; but they are so with the skate, whose 

 head and whole body are equally disposed on either side a longi- 

 tudinal section. Hence the eyes of this fish are placed sym- 

 metrically upon the uppermost side." Philosophic Zoologique, 

 torn, i., pp. 250, 251. Edition C. Martins. Paris, 1873. 



276 



