370 ALFRED GIBBS BOURNE. 



I have even after most careful examination of specimens, 

 mounted whole and of sections, been unable to find any cases 

 of nuclear division. 



Other Protoplasmic Contents. 



I have already spoken of the chlorophyllogenous substance, 

 the permanent vacuoles, and the sand particles. 



In addition to these, I have observed in many individuals 

 small globular refractive bodies, about ywoI) ii^ch in diameter, 

 which, from the fact that they are blackened by osmic acid, I 

 suspect to be of a fatty nature. They are much more nume- 

 rous at some times than at others. 



I have on two or three occasions found all the specimens 

 then examined crowded with large (about ^^ inch in dia- 

 meter) disc or lens-shaped, fairly transparent, but not highly 

 refracting bodies, which, from the fact that all these specimens 

 had been feeding on some special substance, I believe to be 

 nutritive bodies of some kind. I have very little doubt from 

 the appearance of the debris that the food on these occasions 

 had been Spirogyra filaments, but I was never fortunate 

 enough to see them in the protoplasm in an undigested state. 

 The protoplasm in all these individuals was simply crammed 

 with the food debris. It is probable that these specimens had 

 got hold of some Spirogyra, of which there was a little on the 

 surface of the mud, and that it had proved a very easily digest- 

 ible food, and that a great deal of nutriment had become 

 stored up in the protoplasm. The bodies under discussion 

 stain a rich deep colour with iodine, but do not lose the 

 colour on warmiug. They are probably some amyloid sub- 

 stance. 



P. viridis takes in plenty of solid food of all kinds, Daph- 

 nise, Ostracods, Diatoms, Naids, &c. I have also found 

 specimens which had taken in two or three or more plants of 

 what I believe to be Wolf fia arrhiza (one of the Lemnaceac), 

 and which swarms in most of the tanks in Madras, and is b}'- 

 the-bye often eaten, curiously enough, in enormous quantities 

 by the tank frogs. 



