76 Instincts, Habits, and Adaptations 
the eyes and the brain, caused by the growth of the facial carti- 
lages. 
5. The migrating eye moves through an arc of about 120 
degrees. 
Fig. 58.—Platophrys lunatus (Linneus), the Wide-eyed Flounder. Family 
Pleuronectide. Cuba. (From nature by Mrs. H. C. Nash.) 
6. The greater part of this rotation (three-fourths of it in 
P. americanus) is a rapid process, taking not more than three 
days. 
7. The anterior ethmoidal region is not so strongly influ- 
enced by the twisting as the ~~ a 
ocular region. == : 
8. The location of the olfac- ae : ; 
tory nerves (in the adult) shows Fie. 59.— Young Flounder, just 
that the morphological midline hatched, with symmetrical eyes. 
follows the interorbital septum,  (“/ter & B+ Williams.) 
9. The cartilage mass lying in the front part of the orbit of 
the adult eye is a separate anterior structure in the larva. 
ro. With unimportant differences, the process of meta- 
morphosis in the sinistral fish is parallel to that in the dextral 
fish. 
11. The original location of the eye is indicated in the adult 
by the direction first taken, as they leave the brain, by those 
cranial nerves having to do with the transposed eye. 
