1894 THE MICROSCOPE. 169 



Another Note on Mr. Cunningham's paper on the Animality 

 of the Diatom. 



By ARTHUR M. E^DWARDS, M. D. 



NEWARK, N. J. 



I did not intend to notice Mr. Cunningham's paper in 

 the August number of the Microscopical Journal 

 because I did not think it worth noticing. There are 

 enough idle papers written on microscopy and if an ob- 

 server tries to answer all, his work maybe endless. But 

 it has called forth a note on the errors in practical micro- 

 scopy in Mr. C's paper, from Dr. Stokes, which is pub- 

 lished in the October number. I let that pass. I think 

 that Dr. Stokes has pointed out the errors in a mild 

 spirit. I cannot let the errors in way of the Diatoms 

 pass so easily. And I wish to say something about the 

 animality of the Diatom itself. That the Diatom is an 

 animal, of course with Dr. Stokes I do not believe. 



What is an animal ? And what is a vegetable ? And 

 how can one state be proved more than another by any 

 optical method ? Is an animal something that takes in 

 oxygen and gives off carbonic acid ? Is a vegetable 

 something that takes in carbonic acid and gives off oxy- 

 gen ? And what are those things, the fungi for instance 

 that do neither ? And can one organism be proved an 

 animal or a vegetable by optical powers ? I think not. 

 Now I do not wish to attack Mr. Cunningham personally, 

 for personally he is my friend, but I do wish to attack 

 his theories as to the animality of the Diatom, l^o opti- 

 cal appliance better put together than his impossible con- 

 trivance will be sufficient to prove or make others see 

 that the Diatoms are animals. I mean the Bacillariacese. 

 For that is the whole individual, — be it animal or be it 

 vegetable or be it protiston. The Diatom is the siliceous 

 shell of a prepared Bacillarian. Bacillariacese are not 

 vegetables and are not animals, but are something hav- 

 ing animal and vegetable properties, — in short protista. 



