268 THE AMERICAN MONTHLY [November, 



cover-glass and slide, and examined in water or some indifferent 

 menstrum. The}' may easily be demonstrated as cover-glass 

 preparations and by staining with gentian violet. The rodlets 

 are 6-8 !j. long, and usually slightly curved. The ends stain 

 deeply, while the middle part remains as a clear space. Sections 

 exhibit the structure and relations of these bodies even better than 

 cover-glass preparations. The material should be fixed with 

 alcohol and stained with logwood, or by Gram's method. 



The rodlets are seen singlv or in pairs, the pairs being shorter 

 than the single rods. In some cases there is an expansion at the 

 ends which seems constricted off' from the rod. vSimilar appear- 

 ances were observed in some eggs of these insects. 



Besides the two insects mentioned, the rodlets were found in 

 many ants wherein they are longer, measuring 10-12 //, and ex- 

 hibiting in the middle a strongly refracting corpuscle, which be- 

 came more visible after treatment with i per cent, acetic acid. 



With regard to these bodies the important question arises 

 whether we have to deal with bacteria living in symbiosis with 

 the insects, or whether the bodies are products of the cells in 

 which they are found. In support of the former view is the fact 

 that Prazmowski has cultivated the bacterioidal forms of the 

 Leguminosce. while against it are the negative results of the 

 author's own cultivation experiments. 



Decolorizing Bacillus obtained from Sputum. — M. Le- 

 grain isolated from phthisical sputum a bacillus which possesses 

 in a striking degree the faculty of decolorizing solid nutrient 

 media which have been stained with anilin dyes. From the ex- 

 periments carried out, it would seem that this bacillus is identical 

 with a species described by Cazal and Vaillard in the "Annales 

 Pasteur," 1891. This decolorizing potentiality is intimately con- 

 nected with the fact that the bacillus imparts a strong alkaline 

 reaction to the medium in which it thrives. — Jour. Royal Micr. 

 Soc, August^ iSgz. 



Bacterosis of the Grape-vine.— Sigg. G. Cugini and L. 

 ^lacchiati describe in I^e Stazioni Speriin. Ital.. iSgi., a new 

 disease of the vine, which attacks the grapes in northern Italy, 

 causing them first to turn brown, then to become dry and brittle. 

 It is caused by a bacillus, about 3-4 // long and 0.25 // broad, 

 usually solitarv, sometimes united together in twos or threes, 

 rarely into filaments. 



MICROSCOPICAL SOCIETIES. 



Sax Francisco, Cal. — Wm. E. Loy, Secretary. 



July (5, i8g2. — The meeting was not largely attended, owing 

 to the fact that so many members are out of town on their mid- 

 summer vacation. 



