482 SUMMARY OF CURRENT RESEARCHES RELATING TO 



on the development of the fungus ; the formation of sporangia may be 

 prevented by a dry heat of 27° C, though a moist heat at the same 

 temperature favours growth, and he found also that sporangia lose their 

 vitality if kept dry for twenty hours. Zoospores perish in the same 

 conditions in twenty-four hours. McAlpine argues from these facts 

 tbat the disease could not be spread to any great distance by wind-borne 

 spores or sporangia. Diseased potatoes can be completely sterilized 

 without harming the tuber by being subjected to a dry heat of 48-50° C. 

 for four hours. 



Study of Balsaminese.* — Feodor Bucholtz has examined young 

 stages of the subterranean Ascomycete Balsamia. The interior is 

 occupied by chambers, of which the walls lined by the hymenium are 

 irregularly infolded. He found at an early stage that there was evidence 

 of several openings, thus indicating connection with Tnberacea? rather 

 than with Pezizacese. He gives an account of a number of allied genera 

 that he studied, especially Hydnocystis, which has a structure somewhat 

 like that of Balsamia, and an apical opening. Bucholtz finds that the 

 Tnberinese form a connecting link between the Pezizinea? and Helvellinere. 



Development of Trumes.j — G. Boyer has studied the question of 

 truffle growth for some years. The young tubercles of Tuber melano- 

 sporum (the species more particularly studied) appear towards the end 

 of July or in August, and when first detected they were no larger than 

 a small pea ; afterwards they may reach the size of an orange. Though 

 there were no connexions seen with mycelial network, on the surface of 

 the tubercle small isolated fragments of mycelium could be detected by 

 the Microscope. If the truffles were moved they ceased to grow, no 

 matter in what soil they were placed, proving, as Boyer considers, their 

 close association with the roots of the trees called "truffle trees." 



New Observations on Ergot.} — Bob. Stager has studied Olavkeps 

 microrejihala, the form of Ergot on Phragmites communis. He describes 

 the species, and finds that it has a biological form which grows only on 

 Poa annua. He also gives a series of new hosts for Clavicqts purpurea, 

 and discusses the propagation of the fungus by means of insects. 



Oak Mildew.§— Griffon and Maublanc have studied the oak mildew, 

 Oidium quercimim Thiim., and they have concluded that the recent 

 attack which has been so widespread in Europe and so destructive, is 

 due to another mildew which they have named Oidium alphitoides, an 

 exotic species newly introduced. They do not consider that it is a stage 

 of MicrospJisera Alni ; the perfect fruit form is so far unknown. Careful 

 measurements and comparisons of the different species are given by the 

 authors. 



Two Epidemic Mildew Diseases. || — Bolcslau Namyslowski records 

 the occurrence of gooseberry mildew, Sphserot/ieca mors-uvse, in the 

 neighbourhood of Krakau, due as is supposed to the gradual normal 



* Ann. Mycol., viii. (1910) pp. 121-41 (1 pi. and 32 figs.). 



t Comptes "Rendus, cl. (1910) pp. 1253-G. 



% Centralbl. Bakt., xxvii. (190'J) pp. G7-73. 



§ Bull. Soc. Mycol. France, x^cvi. (1910) pp. 132-7 (1 fig.). 



|| Zoitschr. Pflanzenkr., xx. (1910) pp. 236-8. 



