78 



THE AMERICAN MONTHLY 



[April, 



worth while to choose a bright sunny 

 day and collect some of the water- 

 plants, and to look them over in a 

 bottle with a pocket lens. Probably 

 numerous forms of Vorticellas will be 

 found, with water-bears, Daphnias, 

 and Rotifers, and after standing ex- 

 posed to the light for an hour or two 

 it is not unlikely that specimens of the 

 interesting Hydra viridis will be found 

 attached to the sides of the bottle. 



We have often urged our readers to 

 make collections and to send an 

 account of their discoveries to the 

 Journal. It is not necessary to 

 determine the species of the organ- 

 isms, in order to make an instructive 

 article about them. It is sufficient to 

 mention the genus, and this can 

 usually be done from the Microgra- 

 phic Dictionary, or Pritchard's work, 

 if it can be found. The object of 

 writing about the organisms should 

 be to rouse an interest in their study. 

 Many a reader of this Journal is 

 within a few minutes' walk of a pond 

 which teems with interesting objects, 

 which would afford instruction for 

 months, and yet they are never looked 

 for. If a person becomes once 

 thoroughly interested in these exami- 

 nations, he is not likely to lose any 

 opportunity to make collections. We 

 urge our readers, therefore, to begin 

 early, and to send us accounts of the 

 habits of the organisms they find, 

 even if their names are not known. 



CORRESPONDENCE. 



To THE Editor : — Apropos to the 

 discussion of the question : What has been 

 accomplished by the modern wide angled 

 glasses .'' while acknowledging that it has 

 not been quite fairly thrust upon you, I 

 think you will enjoy, and that good will 

 be done, by putting side by side two short 

 quotations, the first from the Quarterly 

 Journal of Microscopical Science for 

 1866-67 (London), Vol. VII, N. S., p. 59, 

 and the other from W. Saville Kent's 

 new Manual of the Infusoria, p. 27. 

 The first is as follows : " On the structure 

 and habits of Anthophysa Miilleri, one of 



the Sedentary Monadiform Protozoa, by 

 H. James Clark, A. B., B. S. We have 

 before had to notice the careful studies of 

 the author of this paper, who is devoting 

 his energies to the most detailed study of 

 single species of Infusoria. He observes, 

 with perhaps a little more enthusiasm 

 than accuracy, that the microscopes of the 

 present day are to those of the past, what 

 Cuvier's scalpel was to those of his pre- 

 decessors, and believes that a vast deal is 

 yet to be leart about the Infusoria by the 

 use of the best glasses opticians can pro- 

 duce. This is possible ; at present, how- 

 ever, we have not heard of a single 

 discovery in biological science, acknow- 

 ledged and confirmed as true, which may 

 fairly be said to have been made by the 

 use of a better glass than the quarter inch 

 objective of many years' standing." 



The second quotation is from the in- 

 troductory part of Mr. Kent's admirable 

 work, in which he is giving the history 

 of the progress of scientific knowledge in 

 regard to the Infusoria. 



He says : - 



" The following year (1868) commands 

 a conspicuous position in the bibliography 

 of the present subject, through iis asso- 

 ciation with the discovery by professor 

 H. James Clark, of the Agricultural Col- 

 lege of Pennsylvania, U. S. A., of certain 

 flagellate Infusoria exhibiting an entirely 

 new type of structure, accompanied by 

 his simultaneous announcement that all 

 sponges consist essentially of colonial ag- 

 gregations of similar flagellate animal- 

 cules." Yours Truly, 



J. D. C. 



Cincinnati, March 19th, 1881. 



To THE Editor : — In a vase of river 

 water, which has been kept for over a 

 year, I find growing from time to time, 

 algae often difficult to procure in situ and 

 in quanties sufficient for proper study. 

 Just now there are quantities of Gonium 

 Pectorale of the family Volvocincce which 

 I have never before seen. Its flat, qua- 

 drangular coenobium is well marked with 

 its regular 16 cells, 3 at each side and 4 in 

 the centre, each having two long, vibratile 

 flagella by means of which it rolls about 

 with a rapid motion. Along with this I 

 have found of the Protococcus family 

 Scenedesmus acutus and Ophiocytium 

 cochleare, both of which are rare in this 

 vicinity. Neither the first nor the last 

 are mentioned by Wood. 



A. F. K. 



Ottawa, Canada, 



