HOLMES. [VOL. II. 



dish I noticed that when excrement was passed the abdomen 

 was bent forward and the mass seized by the gnathopods and 

 passed forward, just as it is when the animal is in the nest. 

 There was of course no use in seizing the excrement under the 

 circumstances, but the act was performed in the usual instinctive 

 way nevertheless. 



Timidity and Pugnacity. 



Specimens of Amphithoe are very ready to attack other 

 amphipods that come near and drive them away. The ani- 

 mals appear to be on the alert to prevent any other individual 

 from gaining access to the nest, --so much so that they very 

 frequently spring out at a passing amphipod and bite at it in 

 what appears to be a particularly vicious and hateful manner. 

 The individual attacked does not, so far as I have observed, 

 attempt any defense but precipitately flees from the spot. Any- 

 thing that properly could be called a fight is never engaged in ; 

 a passing nip with the gnathopods, or bite with the jaws, is all 

 that seems to occur in the nature of hostilities. 



While ready to dispute the entrance of another amphipod 

 from in front, Amphithoe generally quickly flees from its nest 

 when an intruder enters from behind. One often sees the 

 occupants of nests routed out by others entering in this way, 

 and I have seen one individual that was expelled by another 

 entering behind it swim around, enter the other end of the 

 nest, and drive out the intruder. Courage in Amphithoe 

 depends in great measure on whether the attack is made from 

 in front or behind. 



Outside the nest Amphithoe is very timid. It does not 

 attack its fellows except by giving an occasional nip when 

 accidentally colliding with them, and it flees quickly when 

 disturbed. It can very rarely be induced to seize meat, how- 

 ever hungry it may be, and however carefully the food be 

 presented. Even when in the nest, care has to be taken in 

 offering the animal food lest it be alarmed by one's move- 

 ments. This alarm is manifested by withdrawing a short dis- 

 tance in the nest. When an animal to which meat is presented 

 withdraws in this way, I find that it is useless to attempt to 



