326 IVILSOX. [Vol. 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 e.xpert, 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 fi.xation could be observed with per- 

 fect ease by placing one of the small parafifine-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, etc., 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 



