F. KITT0N ON THE MYSTERIOUS APPEARANCE OP A DIATOM. 179 



passed through the paper and have continued to increase in the 

 filtered water. In order to test this I filtered some emery powder, 

 which had remained in suspension six or seven hours, the particles 

 of which were less than the -00005 in size ; these I found did not 

 pass through the filter. 



I do not conclude from this that it is a case of spontaneous 

 generation, but rather as indicating the existence of microspores 

 sufficiently minute to pass through the paper. I have some bottles 

 of distilled water, prepared two months ago, none of which exhibit 

 any indications of the existence of Diatoms or other organisms.* 



* The development of ruycelia takes place very rapidly in the distilled 

 water containing cleaned preparations unless it is mixed with at least an 

 equal quantity of spirit. This, I believe, is due to the cork, the bottom of 

 which moulds, and the spores fall into the water and produce mycelia. 



Journ. Q. M. C, Series II , No. 13. 



