Herrick, Zerminal Buds of Fishes. 129 
skin is directly proportional to the number of terminal buds in 
the areas in question. 
Numerous unrelated types of bony fishes from the siluroids 
to the gadoids which possess terminai buds have developed 
specially modified organs to carry the buds and increase their 
efficiency. These organs may take the form of barblets or of 
free filiform fin rays. The free rays of the pelvic and dorsal 
fins of gadoid fishes are thus explained, and indeed this is pos- 
sibly the motive for the migration into the jugular position of 
the pelvic fins of the gadoids. In all cases where terminal 
buds are found on barblets or filiform fin rays gustatory nerves 
belonging to the communis system are distributed to them. 
The fishes in which the cutaneous terminal buds are most 
highly developed are in general bottom feeders of rather slug- 
gish habit and in some cases they are nocturnal feeders. The 
high development of this sense is compensated for in some fishes 
by the reduction of others. The visual power of the fishes is 
especially apt to suffer degradation. This degradation may be 
organic, a positive degeneration of the visual apparatus, as in 
Ameiurus, or it may be merely functional. In the latter case, 
though the organs of vision are not necessarily modified, these 
organs are not actually used in procuring food, the fish being 
unable to effect visual reflexes toward food substances or to cor- 
relate visual stimuli with the movements necessary to react to- 
ward food substances. The fish may be perfectly able to effect 
other visual reflexes, such as avoiding enemies, but is appar- 
ently unable to understand the significance of food when per- 
ceived by the sense of sight only. This particular central re- 
flex path has never been developed, or has atrophied from dis- 
use. Nature has here effected for the species something simi- 
lar to what is accomplished in individual men occasionally by 
disease, in the production of certain aphasias. 
This study has been directed primarily toward the solution 
of a simple physiological problem; but in a purely incidental 
way some points of interest to comparative psychology have 
come up. We have seen that in the cat fish, hake and tom 
cod the reflex of seizing the food is normally set off by a com- 
