Conant does not tell us how cold the water became when he placed ice in it, but judging from his results, it seems that he might have obtained a decided slowing of pulsation if the water in which the medusæ swam had been permitted to approach anywhere near the freezing point, say 35-40° F. Romanes obtained decided slowing of pulsation, and even complete inhibition, on a bell of Aurelia, as also a lengthening of the latent period on some strips cut from a bell of Aurelia, by lowering the temperature of the water. Replacing Aurelia in warmer water had the effect of immediate recovery and increased rhythm. In Aurelia, raising the temperature increased the rhythm but diminished it when the temperature of the water became 70-80° F. After a slowing of pulsation due to such a rise of temperature, it would not quicken again when the animal was placed in water of its normal temperature. Romanes explains this by supposing that the tissue of the medusa had been permanently injured by the abnormally high temperature. It would be interesting to observe how the tropical Aurelia behaved under such treatment, seeing that Charybdea pulsated actively and without apparent injury in water at 92° F. _Limnocodium_, noted by Romanes, and probably a tropical species, lived happily in water at 85° F. in the lily house of the Royal Botanical Society. The temperature of the water could be raised to 100° F. before it proved fatal to this medusa. Such facts point to a decided difference in the constitution of the protoplasm of tropical and temperate medusæ. Romanes’ Sarsia became frantic when placed in milk-warm water. While writing the above, I was led to wonder whether the temperature of the water may not have been the stimulating influence in those experiments on light (previously noted) in which the medusæ continued to swim actively in the sunlight. _Food and Feeding._--See Experiment 36. I again make note of a few observations made by myself on the Olindiad. A crustacean became entangled in the tentacles of a medusa; apparently this wished to retain it, for the proboscis reached in the direction of the crustacean, which, however, got away. I then placed, by means of a needle, another small crustacean against one of the tentacles. This was seized but not retained, for the animal pulsated and it was washed away by the water. Twice I saw a good-sized crustacean in the proboscis. In one instance the velum appeared to hold the part of the crustacean not yet in the proboscis. I noticed another with a crustacean wholly in the proboscis, which was much lengthened out, the upper part of the crustacean being in the stomach. The next morning the crustacean was wholly in the stomach and the proboscis normal. At 5.30 P. M. the crustacean was ejected, nothing but the shell and some rubbish remaining. These medusæ seem to pay no attention to being touched by one of their kind, except to give a pulsation or two.