118 EXPERIMENT STATION RECORD. 



The latent life of the TJredineae, J. Eriksson (Compt. Rend. Acad 

 Sci. Paris, 124 (1897), Ao. ft, pp. 475-477). — After recounting some of the 

 principal methods of infection that have been observed in the rusts, 

 the author gives an account of two seemingly inexplicable infections. 

 Plants of wheat and barley, which are especially subject to attacks of 

 Puccinia glumarum, were grown in large glass tubes containing steril- 

 ized soil or in a specially constructed glass apparatus. The openings 

 were plugged with cotton, and apparently all precautions were taken 

 to prevent infection; yet, after about two months, spots of rust were 

 seen upon the plants. A microscopic examination failed to show the 

 internal presence of any parasite. 



The author states that upon one occasion in examining the outer 

 layers of cells of grains of wheat deformed by rust he found mycelium 

 and often a sort of teleutospore. Every attempt to find the mycelium 

 in the germ or in the recently sprouted plant failed, yet in from four 

 to eight weeks from seeding abundant rust spots were seen upon the 

 plants, and the mycelium was found abundant in the vicinity of the 

 diseased areas. 



As explaining the infection when neither a^cidium, puccinia, nor uredo 

 forms were observed, the author reports Observations made in 1893 

 which he believes show a latent power of the fungus to infect its host. 

 While examining under high power very young rust spots on wheat 

 some peculiar corpuscles were seen in the chlorophyll cells. These 

 special plasmic corpuscles were intermingled with the other contents of 

 the cells, were oblong, slightly curved, and either separate or several 

 were united together. They occur floating freely in the protoplasm or 

 in contact with the cell wall. At other times they were branched and 

 had penetrated the cell wall, forming a soil of mycelium with haustoria 

 still remaining in the cells. Neither corpuscles nor intercellular myce- 

 lium were ever observed at any considerable distance from the rust 

 spots. The author considers these corpuscles as probably a sort of 

 primordial form from which the fungus is developed. It is believed 

 that the fungus exists in the protoplasm of the host in a state of sym- 

 biosis, to which the name '-microplasinic symbiosis" is given. Under 

 the proper external conditions the intimate association which exists 

 between the plasma of the host and parasite is broken up and the cor- 

 puscles and mycelium of the fungus are developed. 



Fixation of atmospheric nitrogen by bacteria from the tuber- 

 cles on leguminous roots, Maze (Ann. fust. Pasteur, 11 (1897), No. 

 l,pp. 44-54). — The author has investigated the ability of the bacteria 

 from tubercles on roots of legumes to assimilate free atmospheric nitro- 

 gen when grown upon artificial culture media. Tin 1 media for two 

 series of experiments consisted of an infusion prepared by boiling 

 uncrushed kidney beans for half an hour. To this was added 2 per cent 

 sugar, 1 per cent chlorate of sodium, a trace of bicarbonate of soda, and 

 the whole solidified by adding L5 per cent gelose. Plate cultures were 



