BACILLARIA 



WHAT ARE THEY ? 



BY 



I*ro±. Arthur MI. EDWARDS, M. I>. 



I use the term Bacillaria so commonly in my everyday 

 conversation that I hâve forgotten the question which I 

 once had to answer and which is put as a title to this pa- 

 per. I hâve also forgotten that the question présents it- 

 self to the scientific mind, the naturalists of yesterday, the 

 biologists of today. And I shall endeavour to answer it. 



The Bacillaria are not Diatomaceœ or Diatoms in com- 

 mon parlance. Diatomaceœ are vege tables, the relicts of 

 the « animalcules » of the older naturalists ; Diatoms is 

 common or vulgar parlance the manner in which the pre- 

 pared shells of Diatomaceœ are spoken of ; Bacillaria is 

 the right name to give to them, because it is older than 

 Diatomaceœ. They look like a faint iron rust coloured 

 skum on the water or as they are mixed with algae they 

 look somewhat green. But remember ail skum that float on 

 the water of ponds and pools is not Bacillaria; it is mostly 

 small organisms that are Protista, neither animal nor ve- 

 getable. In fact the animal nor the vegetable does not 

 exist and it is doubtful if they are not ail Protista or des-» 

 cendents of the Protista. 



