326 WILSON. [Vou. IX, 
of the first. This was done by dipping it out with a two-gallon 
glass aquarium jar, in which the bright red sponge larvae could 
easily be seen swimming about. These were sucked out with 
a pipette and put into an aquarium jar well protected from the 
sun. In observing and dipping at the larvae, the negro boy 
soon became expert, and proved himself of very considerable 
use for this purpose. By the time we had finished examining 
the water of the first tub, the water in the second would 
contain enough larvae to be worth looking through in this 
manner. The sponges were then thrown away and another 
lot collected. 
Having obtained a stock of the swimming larvae (for several 
reasons I had need of a large number) they were then put in 
flat shallow dishes in which I wished them to attach. Many of 
these dishes I coated with paraffine, allowing the larvae to 
attach to the paraffine, as already described for Esperella. In 
other cases the larvae attached to the walls of the dish, or to 
cover-glasses placed on the bottom. As in the case of Espe- 
rella, the whole process of fixation could be observed with per- 
fect ease by placing one of the small paraffine-coated dishes 
on the stage of the microscope, using reflected light and a low 
power. The larvae swim about for a day, as a rule, and then 
attach, undergoing a metamorphosis essentially like that of 
Esperella. The just attached sponge is a thin incrustation-like 
mass, in which the canals, flagellated chambers, e¢c., appear in 
the course of a couple of days. The sponges I reared lived 
indefinitely in the aquaria, but did not increase in size after the 
first two or three days (and that increase was probably one of 
area alone, not of bulk), except in a single case where the little 
sponge, when killed, had reached a diameter of nearly a quarter 
of an inch, but had not gone beyond his brothers in morpho- 
logical differentiation. I attempted to get older stages in a 
way which it certainly seems should have been successful, but 
which was not. Having allowed the larvae to attach to pieces 
of wood or glass, I tied these pieces to the mangrove roots, in 
the very home of the sponge, but even there the little sponges 
did not increase in size. The pieces of wood hung to the 
mangroves were in some cases protected by wire cages, and in 
