1892.] MICEOSCOPIOAL JOURNAL. 71 



ination could be commenced. This was done by transferring material 

 to ordinary slides and examining in the acid. The statoblasts were 

 soon sufficiently transparent to permit a determination of the structure 

 bv a ^ inch objective." 



The Cotton Crop of the United States for fifty years is fully treated 

 in the Americati Agriculturist for January. It gives the crop in 

 bales, total consumption, exports, weight per bale, gross and net, and 

 average price per pound on the plantation, exported at New York and 

 at Liverpool ; also the acres planted, the total yield in pounds, the av- 

 erage per acre in pounds and bales, total value of crop and value per 

 acre. The United States live-stock census from 1S40 to 1S90, inclu- 

 sive, is also given, together with the grain census for the same years. 

 This is supplemented with tables showing for oats, corn, and wheat the 

 acres grown in each State in 1S91, compared with the average for the 

 five previous years, the yield per acre in 1891 and 1890 and in the five 

 previous years ; and the same regarding the total crop, prices on the 

 farm, and total value. This is supplemented by tables showing our 

 agricultural exports and imports and the exports in detail. 



Crustaceous Parasites of Fishes are desired by Professor Kelli- 

 cott for his exhibit at Chicago in 1893. Those interested are desired to 

 read his request among the Want, Sale, and Exchange notices. 



DIATOMS. 



Life History — their Classification. — An article with this title re- 

 cently appeared in this yotirnal (vol. xi, pp. 276-280 and xii, 1-6, 

 81-85,97-101, 121-123). The Torrey Bulletin for January, 1892, pp. 

 27-2S, contains the following criticisms by C. Henry Kain, of Philadel- 

 phia. After commending in high terms a part of the paper he indicates 

 a few errors or inaccuracies, of which our readers should have the ben- 

 efit. 



" The division into fresh water and marine genera is not at all a happy 

 one. Of the 34 genera enumerated as fresh water, 11 are also marine 

 while 2 others are exclusively marine ( Terpsinoe and Sckizonema) . 

 Nearly all the species of Pletirosigfua are either marine or brackish. 

 Some of the most interesting forms commonly found in marine collec- 

 tions are absent from the list of marine genera ( Coscinodiscus^ Aniphi- 

 ■prova^ ActinoptycJiJis and Actitiocyclus) . 



" In telling how to distinguish Campylodiscus^ Surirella^ and 

 Cy77iatopleitra^ the statement is that if the frustrule is twisted the spec- 

 imen is Ca?jtpylodiscus, but the other two forms are frequently twisted. 

 The old term, " saddle-shaped," would be a more expressive one. 



He says that there is certainly no better guide to the determin- 

 ation of genera than is given by H. L. Smith in the " Conspectus of 

 the Diatomacese," which has been reprinted in WoUe's Diatomacea; 

 of North America. 



BACTERIOLOGY. 



The Influenza Bacillus. — At the Academy of Medicine in Paris 

 (Feb. 9) Cornil and Chantemesse performed an interesting experi- 



