334 Mr. H. J. Carter on Zoosperms in Spongilla. 



Fig. 21. Commencement of gemmation. 



Figs. 22, 23. The body of Difflugia divided into four spores. 



Fig. 24. The body divided into granules. 



Fig. 25. Chilomonas paramecium :— a, reddish vesicle ; b, lines indicating 



the furrows of bisection ; c, nucleus. The dark granules are 



starch. 



XXX.— Zoosperms in Spongilla. By H. J. Carter, Esq. 



[With a Plate.] 



Having resolved to watch for the antheridia and their spiral 

 filaments, as they became developed this monsoon in the mosses 

 and smaller cryptogamic plants of the island of Bombay, the 

 thought struck me that I might include Spongilla, which also 

 grows rapidly a few weeks after the commencement of the rains. 

 I therefore, about the 1st of July, threw several handfuls of 

 Spongilla, previously broken up for the purpose, on the surface of 

 the water of a tank which had been dry for some weeks before 

 the monsoon began, and which was now filled. 



On the 20th July I visited the tank, and found these portions 

 of Spongilla in many places attached to the under sides of dead 

 leaves, and matting up bits of straw and other floating substances 

 under a superficial layer of green, slimy conferva. Some of the 

 portions were an inch long in their new, projecting, mammiform 

 parts. 



On examining the structure of the latter internally, I found 

 the old deciduous capsules at the base, but could discover no 

 new ones sufficiently developed to be recognized. 



A mammiform projection was then selected, which from its 

 light colour appeared to possess no foreign material, and from 

 this a small piece was cut out, which, having been washed to 

 clear it still further from all impurities, was torn to pieces as 

 much as possible in water, and the whole placed under a mag- 

 nifying power of 500 diameters. 



Here the trembling motion of the fragments of Spongilla, 

 always present under such circumstances, was immediately per- 

 ceived, and on searching more narrowly for the cause of this, it 

 was seen to be owing to minute hair-like filaments in rapid 

 motion, which projected outwards from the sides of the principal 

 masses, very much like cilia. On endeavouring however to find 

 out if these filaments were attached to any definite forms, and 

 selecting for this purpose the smallest and most isolated frag- 

 ments which presented the tremulous motion, I saw that they 

 consisted in each instance of a spherical cell, to which was 

 attached the hair-like appendage mentioned (PI. XI*. fig. 1). 



