DISEASES OF PLANTS. ( <7 



possible mode of propagation the necessity for proper seed selection and grading in 

 farm practice will become very evident. 



Symbiosis in Lolium, A. Nestler (SUzber. A'. Akad. Wis*. [ Vienna], Math. Naturw. 

 A'/., 118 i 1904), No. 8 9, pp. 529-546, pi. 1; abs. in Bot. Centbl, 98 1 1905), No. 18,pp. 

 461, 452). — A brief review of literature relating to the fungus occurring in Lolium 

 temulentum, L. perenne, and other species is given, after which the author describes 

 investigations with the two above-namea species, experiments on the pure cultures 

 of the fungus from the darnel, and a peculiar malformation thai is possibly due to the 

 fungus. 



The fungus is said to be found only in the stems during the growing season and 

 never in the leaves or roots, and there seems to be a true symbiosis be1 ween the hosl 

 and the parasite. The author could uol find any evidence to show thai the grain of 

 the infested plants was any better developed than those free from the fungus. A 

 greater proportion of seeds of L. temulentum is affected by the fungus than of /.. 

 i>, r, nm . only 28 per cent of the latter being found t<> contain tin- fungus hyphse. It 

 is thought that the symbiosis between the fungus and the perennial rye grass is qoI 



as yet s<> well established a- i- the case With the darnel. 



A description is given of a curious growth in many seedlings of darnel. The grow- 

 ing stein seems in sonic way to he caught in the leaf sheath, causing it to form a loop, 



which finally bursts through and resumes its uprighl growth. Thai this is wholly 

 due to the presence of the fungus is questioned. 



A contribution to the biology of ergots, R. Stages ( ( 'entbl. Bald, [etc], 2. .1/-/., 

 14 [i:io:>\, X<>. j, j, t ,. 25-82). — In a previous publication I I-'.. S. R., !»'•. p. 985) atten- 

 tion w as called to inoculation experiments with various species of Claviceps. in which 

 biological races were shown for the fungus. The identity of several species which 

 had been hitherto considered distinct was pointed out, hut the identity of species 

 occurring on Brachypodium sylvaticum and on Milium effusum was not fully determined. 



In the present paper the same species of Claviceps is said to infest each of the above 

 species of grass, as was shown by numerous inoculation experiments, and the author 

 believes that this species is probably a biological form of the ergot occurring on rye. 

 It is believed probable that in nature this species is able to infest through its bio- 

 logical forms both of the species of grass enumerated above. There seems to he a 

 kind of hetercacism between the different forms. On Milium the ergot torn is conidia 

 and very rarely normal sclerotia, while upon Brachypodium it forms conidia and 

 well-developed sclerotia. 



Black scab of potatoes, J. W. Eastham (Year Book Col. Agr. and Efort. Holmes 

 Chapel, 1904,pp. 11-18, pi. t). — A description is given of the black scab of potatoes, 

 due to Chrysophlyctia endobiotica. This disease was first noticed and described on 

 potatoes grown in Hungary in 1896, and was first recorded in Great Britain in 1900. 

 Since that time it has spread to various parts of Great Britain, in some cases causing 

 considerable loss. 



The disease must not he confounded with the true BCab, w hidi forms rusty patches 

 caused by a corky thickening of the epidermis of the potato. In the black scat* the 

 potato put- out various excrescences, which are of irregular growth, wrinkled, and 

 wartlike. Not only the tubers, hut the underground stems and the l>ase< of the 

 stems above ground are subject to attack by this fungus. 



Investigations have shown that the fungus is capable of withstanding the action of 

 lime, fn.st. etc., when in a resting stage, and that it- attacks are mofll severe on light 

 dry soils. 



A> preventive treatment, the author suggests the destruction of all diseased pota- 

 to,- by burning, or feeding them after being thoroughly cooked. Winter plowing 

 or the use of lime in autumn or winter seems to be without effect, although the 

 application of lime in May has apparently some influence in retarding the disease. 



