1898.] MICROSCOPICAL JOURNAL. 211 



tinous matrix from the attacks of the Ciliata and Amoeba, 

 I hoped they would survive long enough to develope 

 sufficiently to settle this question, and I watched them 

 with great interest from day to day. That there should 

 have been so many of these peculiar growths I thought 

 remarkable. I had often before noticed the tendency of 

 the desmids to climb upon projecting points, and prob- 

 ably the buoyancy given by the gases liberated by their 

 vital processes was sufficient to stretch out the yielding 

 gelatinous envelope of the diatoms into this shape. 



Destructive animals did not appear very abundant. 

 There were many rotifers but tliey live upon minute or- 

 ganisms circulating in the water. Around the root and 

 climbing upon the stem of this growth under examina- 

 tion, I counted fifteen, of those very curious sloth-like 

 creatures, the Tardigrade or Water Bear. Some of these 

 were very large, but, as the contents of their stomachs 

 was colorless, they did not appear to have been feeding 

 upon diatoms. Although I have watched these animals 

 for a considerable time in hundreds of instances, I have 

 never seen them feed. ^Notwithstanding, their formidable 

 claws do not appear to me to be very destructive. Their 

 comical contortions while painfully clambering over the 

 debris look appealing rather than ferocious. 



In a very few days it became evident that these growths 

 were being rapidly devoured. Every morning a larger 

 tract was cleared until finally all were gone. I then 

 poured off the whole and strained it through a fine 

 wire sieve, capturing a large number of that miser- 

 able crustacean, the aquactic representative of the common 

 sow bug, a freshwater relative of the so-called sandflea 

 of the seashore. This is the most omniverous destroyer I 

 know. Fish, flesh and fowl come alike to him including 

 animals, plants, vegetables, algse, fungus, desmids, and 

 diatoms ; and he will even devour their empty shells. 

 During the three years that have passed since these oc- 



