79 JOURNAL OF THE 
the inauguration of experiments I should reccommend the 
months of July, August, and September. 
It is easy to determine when one of the horny or 
silicious sponges is breeding. On cutting out a piece of 
the sponge, the developing eggs scattered theugh the 
tissues can be seen without the help of a lens, They are 
minute, rounded bodies, often very numerous, and suf- 
ficiently conspicuous to catch an observant eye. 
The means employed for getting young sponges must 
always be different from those made use of in the case 
of animals like fish, oysters, etc., in which artificial fer- 
tilization is practicable. Since the sponge egg is 
fertilized and undergoes its early development in the 
body of the mother, artificial fertilization is here of course 
out of the question. 
The young in numbers ample for study can, however, 
~ be obtained in the following easy manner. ‘Thesponge 
being raised to near the surface of the water is then dip- 
ped up ina glass aquarium or bucket, in such a way as 
not to expose the animal to the air, In a few minutes 
time the ciliated larvae will begin to be discharged. In 
the study of some Bahama sponges I found it convenient 
to take to the sponge-grounds, ina boat, a couple of good 
sized tubs. In one of these some sponges would be 
placed for about half an hour. At the end of that trme 
they were transferred to the second tub. The water of 
the first tub was meanwhile examined for the sponge 
larvae. In this I was aided by negro boys, who soon 
became expert. We bailed out the water in 2-gallon 
glass vessels in which the little larvae could readily be 
seen, ‘The latter were then picked out with glass tubes 
-and placed in aspecial dish. By the time the examination 
of the frst tub was completed, the second would be found 
to contain numbers of larvae. These were collected in 
the same way, the sponges being thrown overboard, 
