THE SYNAPTAS OF THE NEW ENGLAND COAST. 
29 
microscope, of course the otolith appears to rise.) If the slide be turned around 
slowly the otolith keeps constantly at the lowest point, though kept out from the wall 
and in motion by the cilia. 
In the case of 8. vivipara I expressed the opinion that this otolith or vesiculated 
cell floated in the liquid and by touching the cilia or sensory hairs at the highest 
point gave rise to sensations of changed position. Now I am convinced that the 
inclosed cell does not float at all but always rests upon the cilia at the lowest point, 
thus arousiug new sensations with every change of position. That the animal is 
affected by change of position was proven by the following experiment: Synaptas 
were placed on a piece of thin board which sloped sharply to the bottom of a dish of 
sea water. They always sought the bottom of the dish, no matter in what position 
they were placed on the board. Not a single instance occurred of the animal crawling 
upward. A single synapta was placed on the board and after it was well started on 
its way down the slope the board was very gently reversed so that the lower end 
became the higher. As soon as the board passed beyond the horizontal plane the 
synapta would stop and as the slope became greater it would turn and start back in 
the opposite direction, and every change in the slope of the board caused a reversal 
of direction in the movement of the synapta. This experiment was tried a number of 
times and on different individuals, but with unvarying results. The change in the 
position of the board was accomplished with the least possible disturbance of the 
water, and no one who saw the actions of the synaptas could doubt that it was 
the change of position which caused the change in the movement of the animal. In 
the light of these facts and the entire absence of any evidence to show that sound 
vibrations of any sort can be detected by these or any other organs, it would seem out 
of place to speak of them as “auditory” organs or even as otocysts , and I suggest the 
name positional organs. 
A number of experiments were made to determine if possible the function of the 
ciliated funnels, and while the results were not entirely satisfactory they throw some 
light, I think, on the use of these curious organs. A large amount of carmine was 
thoroughly mixed with clean sand and, after it had settled and fresh sea-water had run 
over it for a little while, half a dozen specimens of inlmrens were placed in the dish. 
They lived in the brightly colored sand for one week and were then washed and killed. 
They showed a very decided pink tinge, which was due only in a very slight degree to 
the carmine attached to the skin externally. Microscopic examination showed that in 
the connective tissues there were numerous reddish-brown granules and these were 
most abundant near the lines of ciliated funnels. No such granules were ever found 
in synaptas living in sand free from carmine. 
While this experiment seemed to indicate that carmine taken in with the sand 
was in some way absorbed and formed the granules, it does not show that the ciliated 
funnels were in any direct way connected with the process. Accordingly another line 
of experiments was begun, carmine mixed with sea-water or the body-cavity fluid of 
other synaptas being injected directly into the body cavity by means of a fine canula 
through the body wall. Synaptas so treated were then killed at intervals of about 
twenty-five minutes for two or three hours, and then at intervals of several hours up 
to twenty-four. It was found that in a very few minutes the carmine began to gather 
along the lines of funnels and in a shorter or longer time, according to the individual 
synapta, the body would resume its normal more or less transparent whiteness, except 
along those lines which appeared as dark-red longitudinal stripes. An examination 
