190 SUMMARY OF CURRENT RESEARCHES RELATING TO 



American Pholiotse.* — Edward T. Harper has made a study of 

 species of PhoUota that are to be found in the region of the Great Lakes. 

 The genus is characterized by the distinct ring on the stalk and by the 

 rusty or ochraceous spores ; but Harper finds that in some species the 

 spores verge on the purple colour of the Stropharise, and that in others 

 there is only a very thin and scanty ring. He finds also that individuals 

 of the same species vary very considerably. Certain species grow on the 

 trunks of trees and are very harmful, others on stumps and logs, and a 

 third series are terricolous. A number of the species described are 

 familiar European plants, others are evidently peculiar to America. Most 

 of the species are represented in beautiful photographic plates. 



Merulius lacrymans and M. silvester.f — C. Wehmer has carried 

 out a series of culture experiments to determine if the above species of 

 Merulius — one of which is the dry-rot of inhabited houses and the 

 other a wood form — were the same species. He has found a marked 

 difPerence in the two cultures with regard to the colour of the mycelium. 

 In M. lacrymans the superficial mycelium is a deep yellow or reddish- 

 brown, the immersed mycelium entirely red-brown, while the solution in 

 which it was grown became golden-yellow. In J/. Silvester the super- 

 ficial covering of hyphae is whitish-grey, the filament deeper in the 

 culture entirely colourless : the solution in the latter case is partly colour- 

 less and partly clear yellow. There are slight morphological peculiarities 

 that bear out the differences between the two species. 



HymenogastraceaB of Tasmania. | — Leonard Rodway describes the 

 different members of this family of irregular spherical underground fungi 

 in which the spores are borne on basidia that line irregular chambers or 

 convoluted tubes. The spores escape by the breaking down of the fruit- 

 ing body, and dispersal takes place by rotting, or more often by small 

 marsupials eating the fungus. There are six genera of this rather small 

 family represented in Tasmania, and descriptions are given of these and 

 of the species. Notes are also given as to the history and biology of 

 these underground fungi. 



Influence of Environment on the Lower Fungi. § — Among the 

 external influences tested by Laurent Ray baud are light aiid heat and 

 moisture. In connexion with the latter considerable change was 

 observed in Rhizopus nigricans with an augmentation of transpiration: 

 the stolons became less numerous : the sporangiophores were shorter 

 and were produced singly ; the rhizoids tended to disappear : the 

 sporangiophores broadened out immediately below the sporangium, and 

 the form of the columella was "changed ; occasionally the sporangiophore 

 branched ; finally the spores were modified in form and became unequal 

 and irregular. The effect of nuti'ition with acid or alkaline media 

 was also a subject of observation. 



* Wis. Acad. Sci., xvii. (191i^) pp. 470-502 (32 pis.), 

 t Ber. Deutsch. Bot. Gesell., ix. (1912) pp. 601-4. 

 X Proc. Roy. Soc. Tasmania, (1911) pp. 21-31. 

 § Rev. Gen. Bot., xxiv. (1912) pp. 392-402. 



