218 SUMMARY OF CURRENT RESEARCHES RELATING TO 



by the sclerotia of Glaviceps which develop in the grass heads. In some 

 pastures 90 p.c. of old grass heads showed infection. The sclerotia 

 when mature are globular in shape. They fall to the ground in autumn, 

 and germinate in spring when the grasses begin to flower, the pistil of 

 the flower being attacked by the germinating spores, which are probably 

 carried by insects. The fungus produces a peculiar nervousness, and in 

 the end may be fatal. Moving pastures one or more times, as mature 

 sclerotia threaten to become abundant, is an effective method of prevent- 

 ing poisoning. 



Effect of Fusarium on Potato Tubers.* — L. A. Hawkins has 

 shown by a series of experiments in connexion with the nutrition of 

 fungi, that generally the fungi in the potato " reduce the contents of 

 sugar, both sucrose and reducing sugar, pentosans, galactans and dry 

 matter. The starch and methyl pentosans are apparently not affected 

 appreciably, and the crude-fibre content was not reduced." It was 

 shown that the two species Fusarium radicicola and F. oxysporum, both 

 of them tuber-rot fungi, secrete sucrase, maltase, xylanase and diastase, 

 and that the diastase is apparently incapable of acting on unaltered 

 starch grains. When potato starch is gelatinized it is then readily 

 hydrolyzed by the enzymes. The fungi grow for the most part in the 

 cell-walls and are thus set ii;i close contact with the starch grains. 



Aspergillus niger Group.-j- — C. Thorn and J. N. Currie give us a 

 cultural study of the species grouped round Aspergillus niger. They 

 grow under a wide range of cultural conditions. The range of morpho- 

 logical characters point to the existence of a series of closely related 

 strains in which the differences are shown in measurement of parts, 

 intensities of colour, and quantitative differences i^i the production of 

 particular reactions. The writers gather from their results that A, niger, 

 as commonly understood, belongs to an unstable or mutating group, 

 comparable to OEnothera spp. They reject the generic name 'SS/er/^- 

 matoctjstis,'" based on the character of the sterigmata ; they see no 

 evidence for separating the species of that genus from Aspergillus. They 

 have grouped the many species described under representatives of 

 sections. These are : A. nanus, the diminutive form ; A. niger, with 

 primary sterigmata, 20-30 /a in length ; A.pluenicis, with three sterigmata, 

 about 50 /x in length ; A. pulverulent us, or A. Strychni, with very long 

 sterigmata ; A. Carhonarius, with long sterigmata and very long conidia, 

 from 5*5/Ato 10*5/Ain diameter. 



Endophyllum Spores.j — F. and Madame Moreau find that the 

 gecidiospore of E. Euphorhise-silvaticae is constantly bi-nucleate. The 

 two nuclei pass into the promycelium, and there divide. There is at no 

 time any karyogamy. 



* Journ. Agric. Research, vi. (1916) pp. 183-96. 



t Journ. Agric. Research, vii. (1918) pp. 1-15. 



i Bull. Soc. Mycol., Prance, xxxiii. (1918) pp. 97-9 (5 figs.). 



