14 JOURNAL OF MARINE ZOOLOGY AND MICROSCOPY. 



quarters of an hour with more or less regularity — in fact until 

 all the ova had been passed out. By this means the ova instead 

 of accumulating in a heap around the opening of the tube were 

 spread as a thin layer over quite a large circular area — not less 

 than 10 inches across, in still water. 



Very shortly after the beginning of the operation, a neigh- 

 bouring individual began to manifest signs of a certain unusual 

 excitement, and in a few minutes, from the centre of its filaments, 

 there arose a thin greyish cloud, in appearance and form like smoke 

 wreaths curling lazily upwards from some sleepy hamlet on a breath- 

 less summer afternoon. A ' male it was that had become aware of 

 the call that was being made, and the cloud that was rising slowly 

 was composed of a multitude of spermatozoa that were being ejected. 

 Unlike the female, the dispersion was not aided by any sudden 

 retraction, the reason being that on account of the minute size of 

 the sperm elements they floated quite a considerable distance (6 to 

 7 inches) in even the calm water of an Aquarium, before settling to 

 the bottom and there meeting and fertilizing the ova that had been 

 ejected just prior. These two had not been busy for long when one 

 after another the other individuals in the tank took up the tale in 

 the same manner, and before the day was done all had finished. 

 Apparently, in these animals, to avoid undue waste, the genital 

 products are ripened nearly simultaneously, and experience some 

 quickening or rather determining sensation when one among them 

 begins to discharge, and which causes them to follow suit imme- 

 diately. What this influence is would be very difficult to determine. 

 We know so little of the psychology of the lower animals that we 

 cannot even theorise on the subject with plausibility. 



