ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 713 



presence of mycorhiza and the absence of root-hairs. There has been 

 very little modification in the form of the root due to the fungus. In 

 the interior of the root it does not kill the cells ; it attacks neither 

 nucleus nor protoplasm, and uses only the non-living nutritive sub- 

 stances. Starch always disappears from the cells that have been 

 penetrated by the mycorhiza. 



Growth of Fungi in Artificial Media.* — J. Dauphin cultivated 

 Mortierella polycephala on a series of artificial media such as glycerin. 

 alcohol, salicin, etc. Small doses of alcohol did not prevent the growth 

 of chlamydos] tores and zygospores. The fungus itself does not induce 

 fermentation, unless the alcohol is used as it is formed. A table is 

 given showing the influence of the various substances on the growth of 

 the mycelium and on spore production and spore formation. 



Ilrritabilty- 



Circulation of Protoplasm in the Mucorini.f — Alfred Schroter 

 has been studying the influence of external factors on " circulation " in 

 the hypluB of filamentous fungi. The plants chosen for experiment 

 were Mucor stolonifer and Phycomyces nitens, which were grown from 

 spores. The streaming of the protoplasm is at first acropetal ; if the 

 movement of the plasma had ceased, there was no further hyphal growth. 

 Abundant movement was also noted in the neighbourhood of fruit- 

 formation, where it continues after ceasing in other parts. A diffused 

 light was conducive to active streaming ; more direct and intense light 

 acted unfavourably ; in the dark the movement stopped entirely. The 

 author gives further an account of effects produced by changes of tem- 

 perature and atmospheric conditions, and also by mutilation of the 

 plant by cutting the filaments. But chiefly he found that streaming 

 was influenced by change of concentration in the culture media or by 

 change of atmosphere. In a dry air there was active movement, and 

 in regard to the media there was a streaming of the plasma towards 

 introduced osmotic substances, such as sugar solution, saltpetre, etc. 

 The whole movement is forward and backward, something like the 

 streaming of the plasmodium in the myxomycete. 



Stimulation of Sterigmatocystis.j — Elizabeth Latham has studied 

 the response of this fungus to stimulation by chloroform vapour. She 

 gives an account of the various papers already published on the effects 

 produced by chemical substances on fungi and other plants. As a result 

 of her own experiments, she finds that small quantities of the vapour act 

 as a stimulant to growth, while larger quantities are hurtful or fatal. 

 While growth is increased, there is relatively less sugar consumption 

 and less acid production, indicating greater economy in metabolism. 

 Cultures were made in the nutrient solution recommended by Pfeffer. 

 without any sugar constituent ; there was no growth, showing that the 

 fungus could make no use of the carbon in the chloroform vapour. She 

 also found that the effect of the vapour increased with the rise of tem- 

 perature. 



* Compter Kemlus, cxli. (1905) pp. 533-4. 



T Flora, xov. (1905) pp. 1-30 (9 tigs.). 



J Bull. Torrev Bot. Club, xxxii. (1905) pp. 337-51. 



