241 SUMMARY OF CURRENT RESEARCHES RELATING TO 



especially characteristic of the natural orders Gcsneracere, Acanthacea?, 

 and Labiates, in very few species of which they were not detected, and 

 were found also in plants belonging to a large number of orders of both 

 Dicotyledons and Monocotyledons, as well as in Azolla and Spirogyra. 



The author was frequently able to observe the formation of these 

 bodies directly out of the cell-protoplasm. They resemble in appearance 

 various forms of the Schizomycctcs, micrococcus, bacterium, bacillus, 

 leptothrix, &c. Their microchemical reactions appear to vary, but they 

 are undoubtedly of a protoplasmic nature. They differ from true 

 bacteria in their power of double refraction, but in many cases exhibit 

 a very distinct power of spontaneous motion. They can even be 

 artificially produced out of protoplasm by simple maceration at ordinary 

 temperatures, and the author believes that in this respect they do not 

 differ from true bacteria, which may also, if we judge from analogy, 

 arise directly out of protoplasm without pre-existing germs. 



At all events while still within the cell, and in certain cases also 

 outside it, these structures have a distinct power of multiplication by 

 bipartitiou. The author was unable to detect that they have any 

 faculty of inducing fermentation. The " plastids" combine the charac- 

 ters of true bacteria and of crystalline structures. With the latter 

 they agree in their double refrangibility ; with the former in the cha- 

 racters already mentioned, but display greater resistance to acids and 

 less resistance to staining reagents ; their movements are also more 

 sluggish, and liable to be altogether interrupted under certain conditions. 

 They are bacteria in combination with a doubly refractive mineral 

 substance, a combination to which the author applies the term " incrusta- 

 tion." From all other cell-contents, chlorophyll-grains, chromoplasts, 

 starch-generators, &c, these plastids differ in their rod-like form, and in 

 their power of division when outside the cell. 



Separation of silver by active Albumin.* — In continuation of 

 experiments by Loew and himself, Herr T. Bokorny finds that cells, 

 when placed in an ammoniacal solution of silver, soon die, before any 

 considerable separation of silver has taken place. In this case, there- 

 fore, the silver-reduction takes place only in dead cells, and this is the 

 case also when the cells, after death, are placed for an hour in spring 

 water and then again in the silver solution. The same reaction is also 

 exhibited after killing with a 1 per cent, solution of ammonia, or with 

 various alkaloids, such as strychnine. 



Moderately dilute ammonia produces in the protoplasm, and, in 

 Spirogyra maxima, also in the cell-sap, a separation of granules which 

 possess a strong faculty for separating silver ; this separation of granules 

 does not take place in dead cells or in concentrated solution of ammonia. 

 The author regards these granules as dense aggregations of albuminous 

 substances, produced out of active albumin by a kind of polymerization. 

 They did not exhibit the reactions of albumin, but were stained a bright 

 red-violet in aqueous solution of fuchsin. 



* Pringsbeim's Jabrb. f. Wiss. Bot,, xviii. (1887) pp. 194-217. Cf. this Journal, 

 1883, p. 225 



