1884.] 



MICROSCOPICAL JOURNAL. 



mouth, although Carpenter seems in- 

 clined to think that the individuals of 

 this group have no mouths, admitting, 

 however, that " it seems certain that 

 alimentary particles are received into 

 the interior of the body, becoming en- 

 closed in digestive vesicles." The 

 same distinguished authority intimates 

 that the transverse furrow, or groove, 

 is ciliated and that the flagellum orig- 

 inates at a point near the junction of 

 the depression before alluded to with 

 the furrow. He further calls atten- 

 tion to the interesting fact that the 

 group to which Ceratium belongs " is 

 specially worthy of notice on account 

 of the occasional appearance of some 

 of its forms in extraordinary num- 

 bers." He cites an instance w^hen 

 the water of one of the large ponds in 

 PhcEuix Park, Dublin, was colored 

 brown bv the presence of immense 

 swarms of a genus closely allied to 

 Ceratium. Any possessor of a mi- 

 croscope in this city can verify the 

 existence of this peculiarity in the or- 

 der by tying a piece of linen or mus- 

 lin to a faucet (connected directly 

 with the street pressure) in such a 

 way as to act as a filter, turning on 

 the water with moderate pressure for 

 ten or fifteen minutes, and examin- 

 ing the brownish coating deposited 

 on the cloth. It will be found to con- 

 sist of thousands of these organisms, 

 to the exclusion almost of other forms. 

 Filterings taken from the Western Ad- 

 dition, the Mission, Taylor street, and 

 Sansome street, all show it in pro- 

 digious numbers, so I presume the 

 water supply in any part of the city 

 will yield it. The brownish, floccu- 

 lent looking sediment which many 

 must have seen on the bottom of pitch- 

 ers or glasses containing unfiltered 

 "Spring Valley" is almost entirely 

 composed of the animal. 



The empty carapaces are quite 

 transparent, but the living forms se- 

 crete a brownish granular matter in 

 the body itself or closely adherent to 

 it, and many appear to have attached 

 to them, between the shorter horns or 

 spines, an exceedingly transparent 



globule or sac, which, if watched very 

 attentively, will frequently show a 

 sort of amceboid movement, and 

 which is more or less completely 

 filled with protoplasm, wherein are 

 included numerous highly refractive 

 globules, together with the " red eye," 

 seen by Dr. Hopkins. This red gran- 

 ule is considered by Carpenter to be 

 analogous to similar spots frequently 

 found in Protophytes, antl is probably 

 a nucleated cell. 



In order to obtain living forms, 

 showing the cufious movement be- 

 fore referred to, some care is neces- 

 sary. I have found it best to gently 

 rinse the brown deposit formed on 

 the cloth filter into a very little water, 

 and examine with as little delay as 

 possible. An aqueous solution of tan- 

 nic acid seems to render the outline of 

 the hyaline sac or globule more visi- 

 ble, but apparently kills the animal. 

 By using an ammoniated solution of 

 carmine it will be found that the pro- 

 toplasm is strongly stained, while the 

 carapace itself is entirely unaft'ected. 



For those having the necessary leis- 

 ure and equipment there is room for 

 very interesting research into the life- 

 history of these remarkable organ- 

 isms, whose presence in our water 

 supply in such incalculable numbers 

 renders such observation more than 

 ordinarily impoilant, for the question 

 of whether the wholesomeness of the 

 water is impaired by their presence is 

 certainly well worth investigating. 



[The species of Ceratium de- 

 scribed by Mr. Breckenfeld is also 

 quite common in the water supplied 

 to other cities. We have seen it at 

 various places — in New York in con- 

 siderable abundance — but nowhere 

 has it occurred in our collections in 

 such quantities as is indicated by a 

 mounted slide sent by Mr. Brecken- 

 feld. We have frequently observed 

 the cilia in living specimens. — Ed.] 



o 



Oidiuin Tuckeri — A Fungus of tlie 

 Grape- Vine. 



At a recent meeting of the Bio- 

 logical Society of Washington, Dr. 



