J. STHART THOJISON. 
252 
the cliifiision currente miglu be observed, upon the taste-buds 
of the barbules of Atueiurus, the gustatory reflexes were 
obtained before the diffusing currents, as marked out by tbe 
stained fluid, reached the nostrils. 
In regard to the sense of touch, in iny experiments it 
seemed that the best-defined reflexes are obtained when 
the bait is placed in actual contact with the skin of the 
area under discussion, and this reaction may be regarded 
as a gustatory and co-related tactile response. One also, 
however, obtains well-defined reactions when the food is not 
actually in contact, but only in the proximity of the taste-buds, 
aud this type of response may be regarded as a purely 
gustatory reflex. 
In experiments, which consisted iu using small pieces of 
cotton-wool instead of morsels of food, I also obtained 
tactile reflexes in which the fish on the first occasions 
seized the wool. It appears, however, that contact with 
cotton-wool is not sufficient to maintain the reflex for 
any length of time, and that the respective reflexes of 
taste and touch “can be experimentally isolated by train- 
ing.” As the result of my experiments I am inclined to 
agree with Herrick, who writes : “ The final result seems 
to be that while the tactile sensation is not sufiicient alone to 
maintain the reflex, the addition of the gustatory element 
is sufficient, and therefore that the gustatory element is the 
essential element in setting off the reflex.” In an addendum 
to his valuable paper Herrick after further experimenta- 
tion arrives at the conclusion with which I agree, that 
gustatory stimuli by themselves, aud apart from the co- 
related tactile accompaniment, “ can be localised iu space or 
have a local sign ” ; although the response is not so strong 
and definite as the gustatory plus tactile reflex. 
One tnay, therefore, with Herrick, distinguish four re- 
actions : (1) A vague, seeking reaction, excited by the sense 
of smell, and consisting in an aimless, circling movement; 
(2) a (juick and definite reaction, consisting in a sharp turn 
of the body and rapid seizing of the bait, whicli is obtained 
