414 R. P. COWLES 
EFFECT OF HANDLING ON THE METHOD OF RIGHTING 
It is generally believed that taking hold of the ray of a star- 
fish or an ophiuroid has an effect on its subsequent behavior. I 
thought it worth while to make a series of tests with ophiuroids 
to determine the effect of handling on the method of righting. 
The apparatus used for these trials was a tight, deep, wooden 
bucket, into which no light entered except from above, and even 
this Hght was reduced to a minimum by partial covering. Several 
specimens of Ophiocoma riisei were tested. An ophiuroid was 
picked up by one ray, inverted and placed at the bottom of the 
bucket, which of course contained sea-water. The rays on which 
the ophiuroid righted itself were noted and then the specimen was 
allowed to rest for several minutes. Taking hold of the same ray 
the experiment was repeated five times; then another series of 
five trials were made, taking hold of another ray. In this way 
twenty-five trials were made taking hold of a different ray after 
every five trials. Although the light coming in from above pro- 
bably was not a determining factor in the experiment, yet in order 
to make sure it had no influence, the position of the ophiuroid was 
varied when inverted, so that the handled ray was directed in a 
different direction during each of the five trials, the whole five 
covering the circumference of a circle. 
The results of these trials were very conclusive. Almost 
invariably the ray handled was not used in the righting, although 
sometimes an adjacent ray took part in the reaction. The tend- 
ency to right away from the stimulated ray was very evident. 
However, if unhealthy ophiuroids are used, or if fatigue is pro- 
duced by too many trials closely following one another, the re- 
sults may be different. Similar tests made with the starfish 
Echinaster crassispina showed a like tendency to right away from 
the ray handled, but here the results were not so invariable, in 
fact, one specimen was found in which the ray handled was used 
to right upon, and this same behavior continued even when the 
handled ray was changed. 
