The Comatulids of Torres Strait. 109 



selected specimens did not differ, so far as could be seen, in the manner 

 of the response, but only in the rapidity. Handling individual comat- 

 ulids had no apparent subsequent effect on the specimen. 



Fatigue seems to be, as a rule, easily induced, but in no other respect 

 is there so much individual diversity as in this. Whether the fatigue 

 noted was real or only apparent, there was no means of determining. 

 Nothing was noted with reference to breeding habits. Dr. Tennent 

 found mature spermatozoa in many males of Comatula purpurea, but 

 mature eggs were not noted in any species. Apparently the breeding 

 season was just opening when we came away, the last of October. The 

 shortness of our stay prevented any observations on regeneration or 

 growth. In the following pages, under the heads locomotion, food and 

 feeding, response to light, response to heat, and response to other stimuli, 

 the facts observed are set forth. 



LOCOMOTION. 



To speak of the methods of locomotion in crinoids, or even in comat- 

 ulids, is like speaking of locomotion among birds, in that there is as 

 much difference between different kinds of comatulids as between 

 different kinds of birds, and as birds may either fly or run preponderat- 

 ingly, so comatulids may either commonly swim or creep. So far as the 

 species studied at Maer are concerned, the Comasteridae are creepers, 

 while the other families represented there are swimmers. It was a 

 surprise and disappointment to discover that none of the common 

 comatulids would swim, even in the deep water by the live-car, so 

 that it was not possible to make the observations and experiments 

 with reference to the swimming of comatulids which I had planned. 

 When any of the species of the Comasteridae were placed in the water 

 beside the live-car, they invariably sank to the bottom (about 20 feet) . 

 In the case of Comatella maculata, it was noted that, as a rule, the 

 individual would close the arms orally and vertically over the disk, 

 so that it sank almost like a stone. As soon as it touched bottom, 

 the arms were opened out and the animal began to creep. In the other 

 species, however, the arms were not closed up and so the comatulid 

 floated downward to the bottom much more gradually. With one 

 exception, all efforts to induce swimming movements of the arms in a 

 comasterid completely failed. 



In no case when the individual was on the bottom did mechanical 

 stimulation result in any attempt to swim or in accelerated movements 

 of any kind. Suspending specimens in the water by means of a slender 

 thread gave no results; the arms moved about slowly and with no 

 coordinated effort and with no resulting locomotion. Several indi- 

 viduals were provided with cork floats, so attached as not to interfere 

 with arm-movements; but, with the one exception already referred to, 

 none of them made any effort to swim. The one exception was a 



