1890.] MICROSCOPICAL JOURNAL. 141 



low, but after a tew hours the original trreen returns in its full vividness, 

 then I at once mount in a shallow cell with a portion of fluid." 



Penicillium Glaucum and Corrosive Sublimate. — In the Bota^i- 

 ical Gazette^ March, 1S90, John M. Coulter reports observing a rank 

 growth of Penicillium glaucum on flour paste, which contained about 

 one part in 900 of corrosive sublimate. 



Oidium Albicans. — MM. Linossier and G. Roux state (Comptes 

 Rendus, 1889, p. 75^) '^^'^^^ this fungus under cultivation takes on 

 varied forms according to the nature of the nourishment. Thus if a 

 small quantity of saccharose be present in the liquid, short mycelial fil- 

 aments will be found to exist, these filaments becoming longer as the 

 quantity of sugar increases. 



The character of the fungus varies similarly if glycerine or mannite 

 be present, or if the nourishment consist only of a simple ammoniacal 

 salt. Finally, if the fungus has been cultivated for several generations 

 in a medium wliere it atiects the globular-filamentous form, it more 

 easily takes this form when transported to new media. 



Microscopy at the Paris Exhibition. — The A?inalcs dc Micro- 

 ora/)/i/c h'ds concluded (1890, pp. 168-171) n series of brief articles 

 on the microscopic display at the Paris Exhibition of 1889. This record 

 is very complete, and will doubtless prove a valuable contribution to 

 this branch of science. 



A Powerful Objective. — Dr. Van Heurck announces in the J^o2(r- 

 }ial de Micrograph ie that Zeiss, working from the formulae of Professor 

 Abbe, has succeeded in producing a j'jj inch '' apochromatic " ol)jective 

 with an aperture of 1.63, and so constructed that under suitable condi- 

 tions the whole of this aperture can be utilized. The author states that 

 with this objective he has resolved the entire frustule of Amphlpleura 

 pellucida^ not merely into lines, but into pearls as distinct as he has 

 ever seen on Pleurosigma angulatum. Repeated measurements show 

 these pearls to be arranged in lines separated longitudinally by gyVo 

 part of a millimeter, while the transverse striations are separated by 

 the 3 o\r7r ^^ ^ millimeter (about o.ooooi and 0.000014 inch respectively) . 

 Three of the new glasses have been made at a cost of $3,000 each. 



MICROSCOPICAL SOCIETIES. 



Essex Co., N. J. — F. Vanderpool, Scc'y. 



March 20. — Residence of Mr. G. S. Woolman, Orange, N. J. Sub- 

 ject, Mounting Media. Rev. Mr. Mann, who has done a large amount 

 of work in mounting diatoms, gave to the Society his experience with 

 various media. First, in speaking of glycerine mounts, he said that he 

 had never had one of these fail, and he attributed his good fortune to 

 the employment of what he called " successful cells." By these he 

 meant cells made in some such way as the following : Take a good 

 lacquer like King's red lacquer, ring a number of cells and put them 

 away for several months to dry and harden. When ready to make a 



