140 Jouyjial of Comparative Neurology and Psycliology. 



The behavior of the adult Lhmilus is principally made up 

 of the following movements and reflexes : the respiratory move- 

 ments of the abdominal appendages, the swimming movements 

 of the abdominal and thoracic appendages, v^arious "gill clean- 

 ing" reflexes of the abdominal appendages and the sixth legs, 

 walking movements, and the reflexes of gustation and degluti- 

 tion. Furthermore, it responds to temperature stimuli very 

 strongly and characteristically, also to certain sorts of tactile 

 stimuli, to disturbances of its equilibrium, to chemical stimuli, 

 and is thigmotactic and phototactic. The original plan of the 

 present work was to make a thorough detailed study of the be- 

 havior and reactions during every stage of development from 

 the time the embryo left the q^^ membranes till it attained the 

 adult condition, in its behavior at least. It was hoped that in 

 this way steps in tlie development of the reactions and reflexes 

 could be traced. 



The work was begun in the U. S. Fish Commission La- 

 boratory at Wood's Hole, in July, 1900, and continued through- 

 out the summer. In that time the behavior was studied and 

 the work finished from my point of view (with the exception of 

 the phototactic reaction) up to the stage at which the first 

 moult occurs (end of the so-called "trilobite" stage). During 

 the following fall a preliminary statement of the results obtained 

 was published in Scienec} It was expected at that time that 

 the work would be taken up again the next summer and older 

 stages studied. This, however, proved to be impossible and at 

 no time since have I been able to take up the work again. As 

 it is uncertain when I shall be able to go on with this problem 

 it has seemed desirable to publish the results so far obtained. 

 I wish to put on record the complete statement of the facts 

 made out in the two developmental stages which have so far 

 been investigated. 



It gives me pleasure to make acknowledgement at this 

 point to those who have in one way or another aided in this 

 work. To Professor Wm. Patten, my friend and former 



' N. S. Vol. XII, \o. 311, pp. 927-928, 1900. 



