418 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



ments with those found in nature have given negative results. An 

 account of cultures and experiments is given, with a copious bibliography 

 in which is included the works dealing with the fungi that cause disease. 



Lichens. 



(By A. LoRRAiN Smith, F.L.S.) 



Spanish Lichens.* — A descriptive account of these is given by Ibiza 

 in his " Compendium " of Spanish plants. A critical account of the 

 thallus is given, and the classification adopted is explained, comprising 

 four orders — l^eprarife, Collemeffi, Endocarpe^e, and Gymnocarpea3. 

 About 450 species are recorded for Spain. Many have probably been 

 overlooked. 



Schizop liy ta. 



Schizoraycetes. 



Bacteriology of Rubber Latex.f— Denier and Yernet have investi- 

 gated the flora concerned in the natural coagulation of the latex of 

 Hevea hrasiliensis (the common rubber-tree of commerce), and have 

 succeeded in isolating no less than twenty-six different species of 

 aerobes, or facultative aerobes, and an anaerobe from specimens of latex 

 submitted to examination. The various species isolated included cocci- 

 coccobacilli and bacilh, some of the latter being chromogenic, or possess- 

 ing terminal or median spores. One bacillus of constant biological 

 characters was isolated from all the specimens examined. Its cha- 

 racters were as follows : — Short bacillus with rounded extremities! very 

 motile and not stained by Gram's method. Greyish-white growth on 

 ordinary sloped agar. Vigorous growth on litmus latex serum-agar, with 

 the production of acid and a small quantity of gas. Acid and gas were 

 produced in saccharose and lactose litmus-agar, gas production being 

 particularly well marked in the latter medium. Acid and clot produced 

 in litmus milk. No proteolytic action on egg-white, but liquefaction of 

 gelatin produced. When tubs containing rubber latex were inoculated 

 with culture of this microbe, complete coagulation was produced in 

 twenty-four hours ; but sometimes it was found necessary to accelerate 

 the action by adding sugar. Zinc tubs cannot be used, as the presence 

 of zinc salts inhibits the growth of the micro-organism. 



Affinities of Pseudo-dysentery Bacilli. t — L. Negre has examined 

 a series of cases of pseudo-dysentery at the Pasteur Institute of Algiers. 

 With regard to their action upon sugars, their agglutination reactions, 

 complement fixation reactions, and pathogenic capacities, they appear to 

 belong to a group intermediate between the true dysentery bacilli and 



* Bot. Descr. Comp. Fl. Esp., i. (Madrid, 1906) pp. 427-87(14 fig.). 



t Comptes Rendus, clxv. (1917) pp. 123-6. 



X Ann. de I'lnst. Pasteur, xxxi. (1917) pp. 172-85. 



