320 journal of Comparative Neurology and Psychology. 



pace. (9) Stimulation of the pleopods caused a sharp flexion of 

 the abdomen at first, then in four cases the animal bowed up on the 

 telson and pulled madly at the pleopods with the chelipedes. In 

 one case even a chela was stuck back as if to assist in the work. 

 (10) The telson was merely folded together, in one case the ab- 

 domen was flexed, and in one there was inhibition of a restless 

 movement of the anterior members. (11) On the carapace only 

 four animals reacted, usually with increased restlessness. In two 

 cases there were vigorous attempts to rub the posterior portion of 

 the carapace with the chelipedes. (12) Stimulation of the eyes 

 caused retraction of those organs in every case but one, and in 

 every case the animal rubbed and scraped and dug at the eyes with 

 one, two, or even all the chelipedes on that side, and in one case 

 even with the chela. One animal, in addition to this, pulled at 

 the antennae with the chelae. 



On the whole the reactions to salt were remarkable for their 

 promptness, definiteness and vigor. They w^ere in some respects 

 even more marked than those with acids. Particularly the re- 

 actions from the chelipedes, the pleopods, the carapace and the 

 eyes showed distinctive characteristics. The general nature of the 

 reactions was such as might be considered to indicate that the ex- 

 perience was disagreeable, in contrast with that to meat juice, for 

 instance. 



6. Sugar. — To test the reactions to a sweet stimulus a 40 per 

 cent, solution of sugar was used and five animals were experi- 

 mented on as above, (i and 2) To stimulation of the antenna all 

 the animals responded but usually only with a slight movement of 

 the organ. This was also the prevailing result from the chelae. 

 In one case the chelae were spread, and in another the forceps 

 were closed and the animal grew very quiet. (3) In every case 

 the-antennules were lowered and drawn through the folded max- 

 illipedes, but sometimes this reaction was very slow. (4) The mouth 

 parts showed chewing movements in four cases, and in three cases, 

 the chelipedes were brought to the mouth, drawn through and 

 wiped off^ by the maxillipedes. (5) From the first chelipedes the 

 typical reactions were slight movements, chewing in one case, and 

 in three cases the member stimulated was brought to the mouth and 

 wiped by the maxillipedes. (6, 7 and 8) The second, third and 

 fourth chelipedes responded in every case with slight movements. 

 Some of these were so insignificant as to be almost imperceptible. 



