ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 747 



readily from the spores. Stager considers that he is here dealing with a 

 biological race or races, as the ergots on these grasses are morphologically 

 identical. He records a further series of experiments with an ergot 

 found on Glyceria fluitans. A large number of grasses were again 

 infected with the spores, but only negative results were obtained with 

 these, while the plants of Glyceria fluitans infected at the same time 

 produced the sphacelia stage and later the sclerotia of the fungus. 

 Stager thinks that this ergot is probably identical with Olaviceps Wilsoni 

 Cooke, recorded in England on the same grass, though hitherto the 

 form found in Germany has been considered to be C. purpurea. Experi- 

 ments with ergot taken from Lolium resulted in the infection of species 

 of Lolium and Bromus erectus alone. The Claviceps of Poa annua 

 could not be transferred to any other host. Brachypodium silraticum 

 has also an ergot that is confined to that one host so far as results have 

 shown from the experiments undertaken. The author gives a list of 

 insects that aid in the dissemination of the spores ; they are attracted 

 in large numbers by the honey-dew of the sphacelia stage. 



Observations on the Ergot of Claviceps purpurea.*— C. Engelke 

 obtained pure cultures from the ascospores of the fungus. The developing 

 mycelium broke up into conidia and with these he carried out further 

 infection experiments. These were only successful when made before 

 pollination of the stigma. The hyphse of the fungus penetrated from 

 the stigma to the developing ovule at the base of the ovary, and there 

 the formation of the sclerotium began. No infection took place through 

 the stomata. The honey-dew of the sphacelia stage is but an increased 

 production of fluid by the stigma, owing to the irritation of the tissue 

 by the fungus. It is not a product of the fungus, and is never produced 

 in artificial cultures. The writer proposes to study the substances formed 

 by the fungus in the cultures with a view to the artificial production of 

 those used in medicine. 



Relationship between Pleospora and Helminthosporium.f — H. 

 Diedicke has followed up a previous research on this subject by further 

 observations and cultures. He had established the connection between 

 the two fungus forms and had identified Pleospora trichostoma as the 

 higher form of Helminthosporium gramineum. He finds now that the 

 determination was too general, that on the different grasses there are a 

 number of Pleospora as PI. teres, PI. Aveim. PI. Bromi, PI. graminea r 

 PI. Tritici-repentis, each with its own form of Hehnintlwsporium. From 

 cultures and infections of PI. trichostoma on rye he obtained Alternaria 

 as the conidial form. 



Studies of Erysiphese. J— F. W. Neger has devoted special attention 

 to the function and behaviour of the perithecial appendages of several 

 forms of Erysiphese. He finds that they are hygroscopic and by torsion 

 movements have an important influence in releasing the ripened fruit- 

 bodies. 



Yeast-forms of Fungi.§— H. Will has studied the different forms of 

 budding fungus cells that occur in connection with brewing. He has 



* Zeitschr. angew. Mikr., ix. (1903) pp. 63-5. 

 t Centralbl. Bakt, x. (1903) pp. 52-9. % Tom. cit., pp. 570-3. 



§ Tom. cit., pp. 689-700. 



