1896 THE MICROSCOPE. 69 



smaller specimens of the same species, in the same situ- 

 ation, and with the same movements. The extremity of 

 one of these smaller tubes I cut wholly off, and placed in 

 the live-box of the microscope. Two of the parasites 

 only were on it, which were active at first, but in about 

 an hoar — probably from the exhaustion of the oxygen in 

 the small quantity of water inclosed — they decomposed, 

 or rather disintegrated, the outline dissolving, and the 

 external cells becoming loose and ragged, the whole ani- 

 mal losing its definite form. 



One of these specimens, however, while yet alive and 

 active afforded me an observation of value. I had already 

 associated the form with the Hydroid Polypes, and was 

 inclined to place it in the family CorynidsB, considering 

 the arms to be tentacles, and the head lobe to be homolo- 

 with them in character, but abnormal in form. It ap- 

 peared to be a three-tentacled Coryne, with the tentacles 

 simple instead of capitate. But while I was observing 

 it, I saw it suddenly open the head-lobe, and unfold it 

 into the form of a broad shovel-shaped expanded disk, 

 not however fiat, but with two halves inclining towards 

 each other, like two leaves of a half-opened book. This 

 reminded me of the great sucking-disk of Stauridia pro- 

 ducta, and confirmed my suggestion of the natural affini- 

 ties of the form. 



Formalin in the Zoological and Histological Laboratory. 



D. S. KELLICOTT, 



C^OLUMBUS, O. 



Member of the American Microscopical Society. 



How often in the memory of most of us has the suffer- 

 ing world been startled by the announcement, often by 

 the highest authority, of some wonderful medicine, spe- 

 cific or elixir. These, one after another, have been put to 

 the test and have taken their places among the useful 



