116 THE MICEOSCOPE. 



DEMONSTRATING CYCLOSIS. 

 By E. N. EEYNOLDS, M. D., 



DETROIT, MICH. 



But few objects are so interesting under the instrument as the 

 wonderful Cyclosis in Vallisneria. One can see the trains of 

 green balls chasing each other around the cells, by the hour. 

 In this cold climate, I have been unable until this year, to keep 

 the grass through the winter. Pieces of grass with or without 

 roots will live for some weeks in ajar of water in summer, or 

 in a comfortably warm house in winter. After ice began to 

 form along the edge of Detroit River last fall, I gathered some 

 rootless pieces of Vallisneria also one root of the same with two 

 blades of the grass attached. I placed the lot in a jar of water 

 which I kept in a cold cellar changing the water once in five to 

 ten days. 



Whenever I wished to use a specimen, I broke offtwo bits 

 about I or J inch long each from a blade of the grass. These 

 I laid side by side in a few drops of water on a warm slip of 

 glass, laid a cover-glass on and examined with 1-5 or higher 

 objective. Usually the circulation can be seen at once ; at 

 other times it needs to have the light on it for ten or fifteen 

 minutes in order to start it, two bits of the grass are used be- 

 cause one might tilt the cover-glass. 



The grass on the roots died before the rootless specimens. 

 The latter remained green and alive until February. I enter- 

 tained some friends with a specimen of it on the 19th of Febru- 

 ary. If it had been kept in a warmer location, all would have 

 been dead six or seven weeks earlier. About the end of Feb- 

 ruary I noticed in the case of the specimen with roots that the 

 fine roots and the blades of grass had rotted off the stem, leaving 

 a green stem, of about an inch in length. This I placed in 

 another jar of water and took it up stairs into the living rooms, 

 where it soon sent out new shoots and from it I soon had new 

 grass to use. Had I taken this into the warm room a few weeks 

 earlier, as I shall do next winter, I would have had new grass 

 before the old died. What I learned in this case is that the 

 grass will live much longer when kept at or near freezing point 

 than if it is kept warm; and that the stems between the fine roots 

 and the blades of grass^need to be kept in water in a warm place. 



