1881.] 



MICROSCOPICAL JOURNAL 



39 



them in English as soon as they can be 

 obtained. 



— We have received a circular from 

 the well-known instrument maker, Mr. J. 

 Grunow, of this city, describing a new 

 microscope which he has lately devised, 

 especially for the use of physicians. With 

 one eye-piece and a ^-inch objective, the 

 instrument sells for $46. It has a sliding 

 tube for focussing, and a fine adjustment 

 screw. 



— Dr. George M. Sternberg, has trans- 

 lated Magnin's excellent work on the 

 Bacteria, and it is now published in Eng- 

 lish, making a volume of 227 pages with 

 ten plates. We reserve a more complete 

 notice of the book until next month, 



— We regret to learn that Dr. J. J. 

 Woodward has met with a serious acci- 

 dent, by the falling of his horse about 

 three weeks ago. His left leg was broken 

 and he will therefore be confined to the 

 house for some time to come. 



— We have received from M. A. Booth 

 several specimens of the material which is 

 offered in our" Exchange " column. The 

 diatoms in situ are the best we have 

 seen, and they make fine specimens when 

 mounted as opaque objects. 



MICROSCOPICAL SOCIETIES 



NEW YORK. 



The Secretary desires to correct the 

 minutes as published last month, so that 

 the first line on page 19 will read " by 

 Mr. Warnock with a Tolles y^-" 



At the meeting held January 7th, 

 the President called attention to the 

 method of reproduction of diatoms. Dia- 

 toms are minute unicellular plants, which 

 are distinguished from all other plants by 

 very marked characters. The living pro- 

 toplasm and brownish coloring matter are 

 enclosed in a hard, silicious case, which 

 consists of two distinct valves, correspond- 

 ing to the covers of a pill-box, with con- 

 necting rings, one sliding over the other 

 precisely like the sides of a pill-box. These 

 silicious coverings are often very beauti- 

 fully carved and marked. It is the silicious 

 remains which constitute the infusorial 

 earths, which are often of great extent. 

 Electro silicon is composed entirely of the 

 remains of diatoms, and they are said to 

 abound in tripoli, but this is not true of 

 all kinds of tripoli. The ordinary ptocess 

 cf multiplication in these plants, is by the 

 division of each one into two individuals. 



Two silicious septa form within the case, 

 and then the smaller valve slides out from 

 within the other, just as the bottom comes 

 out of a pill-box, and each valve main- 

 tains an independent existence. A more 

 curious process, however, is by the conju- 

 gation of two individuals. They come 

 together and their contents mingle, form- 

 ing a circular body called the sporange. 

 Within the sporange a so-called auxospore 

 developes, which soon grows so large as 

 to break the sporange, and before long 

 the large auxospore will be seen to con- 

 tain the young diatom. It is a remarkable 

 fact that the infant diatoms are much lar- 

 ger than their parent forms. It can 

 readily be understood that the above 

 described process of division results in a 

 constant reduction in the size of the dia- 

 toms. Hence, the large form whic/n re- 

 sults from conjugation, gives birth to 

 succeeding generations by division, each 

 smaller than its progenitors, and this 

 would continue indefinitely, except for the 

 limit fixed by nature. All these processes 

 take place in organisms so minute that 

 they can hardly be seen with the naked 

 eye, under the most favorable conditions. 



ELMIRA, N. Y. 



Regular meeting, December 30th, 1880. 

 President Gleason in the chair. The 

 usual members were present and a large 

 number of visitors. Mr. Sexton, of Roches- 

 ter, exhibited Gundlach objectives and 

 stands to the Society. The American So- 

 ciety of Microscopists was invited to hold 

 the next meeting in Elmira, under the 

 auspices of the local Society. The regular 

 routine of business having been transacted, 

 Dr. Krackowizer delivered a lecture on 

 " Atoms, Molecules, Cells." 



He spoke of Atoms having assumed 

 centres of attraction, one, two, three or 

 more, by means of which they were drawn 

 toward one another to form molecules. 



He stated that there was no essential, 

 difference between a molecule and the 

 primitive cell, an amceba, for example, 

 chemically considered being but a com- 

 bination of atoms, manifesting such phen- 

 omena of life as locomotion, alimentation, 

 growth, proliferation, etc., sensation and 

 consciousness not being differentiations, 

 but endowments of the higher organism. 



" Darwinism " is at present the best 

 working theory, since it more readily ex- 

 plains the greatest number of facts in 

 every department of human knowledge 

 than any other. 



Judge Dexter was appointed essayist 

 for the next meeting, subject : Evolution. 



