D. B, WARD, M. D. 67 



heated to a white heat without destruction or boiled in 

 strong mineral acids — nitric, sulphuric and hydrochloric 

 without injury — indeed we constantly employ both these 

 methods for the purpose of cleaning the shells for ex- 

 amination. 



Other forms were soon found unmistakably of the 

 same character but which were not free-swimming and 

 were exceedingly plant-like in appearance. Some grow 

 on the ends of minute stalks, the other ends being at- 

 tached to submerged twigs, or stones or water plants ; 

 others grow embedded in long gelatinous tubes which are 

 attached at one end. Others, again, being rectangular 

 and flat, arranged side by side like boards upon a fence, 

 form ribbons of considerable length, while others at- 

 tached by one corner only form ziz zag chains. Some are 

 cyliodrical and form tubes resembling many of the fresh 

 water algae except in color. Others generally oval or 

 round are purely parasitic and are attached to water 

 plants by their fiat surfaces. Again others destitute of 

 motion are loose in the water and lie on the mud or are 

 tangled in weeds. Then, as sometimes happens even in 

 scientific matters, a controversy arose as to the nature of 

 these organisms. Were they animal or vegetable ? And 

 as also sometimes happens when a good deal may be 

 said on both sides, this controversy got a trifle peppery 

 at times. They had been classed among the infusoria 

 and were so classified, even as late as 1861, when the last 

 edition of Pritchard's Infusoria was published. The 

 question was finally settled by Mr. Mathieu Williams, 

 an English chemist. He collected the little bubbles of 

 gas which arose from a mass of living diatoms and found 

 it to be oxygen. Now no animals exhale oxygen but 

 plants do, and the fact that some baci'laria or diatoms 

 move is not at all a strange thing, for many of the lower 

 and even of the higer plants move very freely. 



Last fall Mr. Van Brunt, who formerly resided here, 



6 



