18 LIVING BACILLI IN THE CELLS OF VALLISNERIA. 



ney. There is a little difficulty attending the demonstration, but if the 

 following directions are followed and carried out with other water- 

 plants, I believe these objects will be seen : — A thin section of 

 the cuticle of the leaf of Vallisneria should be sliced off, so as to 

 increase the light passing through the cells. The specimen must 

 be placed on a slide, with the cuticular surface next the cover, 

 and then the slide should be placed on a rest, with the cover 

 downwards or towards the table, and remain there for five minutes 

 at least, in order to allow these organisms to fall on to the cuticu- 

 lar walls of the cells, and then examined under a quarter-inch 

 object-glass - 250 diameters. These bodies must be looked for in 

 the quadrate cells, and will be seen moving about the chlorophyll 

 grains, even when cyclosis may be going on ; and after the lapse 

 of some minutes they will gravitate out of sight, or be found 

 heaped together at the lower end of the cell (or apparent upper 



end). 



It is this circumstance which has prevented any recognition of 

 their presence in this plant. These organisms measure i — 5,000th 

 of an inch in length, possess a distinct motion of their own, and 

 increase in size as the cells lose their vitality. I have obtained 

 these results from specimens of Vallisneria grown under any or 

 all conditions, with the leaves perfectly healthy and green ; from 

 the narrow variety, resembling the European form ; and from our 

 large Australian one, with leaves from five to six feet in length and 

 one inch in breadth and a considerable thickness of lamina, so that 

 sections can be cut " edge on " to the leaf. These objects are 

 rarely, if ever, seen in the long, deep-seated cells, which exhibit 

 cyclosis so beautifully in this variety. After the application of 

 carbolic acid with heat to decolourise the specimen, I have wit- 

 nessed the movement of these Bacilli, although the acid had dis- 

 integrated and disorganised the other cell-contents. So much for 

 vitality ! How much for carbolic acid in directly killing these 

 vermin ? I wish the stipules of Hydrocharis could be examined 

 with a view to determine their presence. A?tac/iaris has yielded 

 some. 



