ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 471 



If infection takes place at a later stage when the grass is coming into 

 bloom, hypertrophy and abnormal developments of the various parts 

 occur, and the flowering is much delayed. The action of the disease 

 is described in grasses of the genera Triticum, Avena, Agropyrum, 

 Glyceria, Phalaris, Lolium, Agrostis, Holcus, and Phragmites. The 

 author recommends the burning of all diseased grasses to prevent the 

 spread of infection. 



Fungus Pests of the Carnations.* — M. C. Corbie gives an account 

 of fungal diseases of carnations. Leaf-spotting is due to the attacks of 

 various species of Sphaeropsideae belonging to the genera Ascochyta, Sep- 

 toria, Gloeosporium, Marsonia, and Cylindrosporium. These render the plant 

 unsightly and weaken the development. Gathering and destroying all 

 spotted leaves would stop the spread of the fungi. Two species of 

 Peronospora have also attacked the leaves of P. Dianthi (not yet recorded 

 in Britain) and P. Arenarise. A Hyphomycete, Ramularia lychnicola, has 

 appeared on wild Lychnis. Heterosporium echinulatum, a black mould, 

 is very destructive to carnations. Macrosporium nobile, a nearly allied 

 mould, has been noted in the West of England, but is comparatively 

 rare. Ustilagineaa and Uredineaa are also frequent pests, and a form of 

 disease is caused by Bacteria. It is as yet confined to the United States. 

 The author gives a list of the fungal parasites. 



Coprophilous Fungi.f — George Massee has chosen for the subject 

 of bis presidential address to the members of the Quekett Club the 

 fungi that are to be found growing on dung. He considers the habitat 

 to be adaptive, as the fungi existed before the animals, though now 

 many of the species are never found on any other substratum. A general 

 sketch is given of the groups likely to occur on dung, and figures in 

 the text illustrate a number of the more interesting forms. 



o 



Influence of Irritation on the Growth of Unicellular Plants.]: — 

 M. J. Trzebinski has carried out a series of experiments and observa- 

 tions on the growth of Phycomyces nitens under the influence of various 

 irritants. Mechanical injury, such as cutting the growing filaments, 

 lowered the turgescence of the hypha3, and markedly retarded growth. 

 A very slight injury was found to act injuriously. Irritation of the 

 sporangium by means of slender glass rods or some similar agent causes 

 increased growth of the stalk. Ether vapour introduced in an open 

 vessel into the culture-chamber also induced more rapid growth. If the 

 vapour were too condensed, growth was entirely stopped. The experi- 

 ments were held to show that between the higher plants and unicellular 

 plants of the type of Phycomyces there is a great similarity in the re- 

 sponse to irritation. 



Resistance to Temperature of Fungi.§ — Abigail O'Brien has tested 

 the comparative resistance to high temperature of the spores and my- 

 celium of delicate fungi. She finds that the mycelium resists heat 

 equally with the spores. The fungus was placed in beet decoction and 

 heated in a boiler to the desired temperature, and then grown in drop- 



* Journ. Roy. Hort. Soc, xxvi. (1902) pp. 649-56 (2 pis.). 

 t Journ. Quek. Micr. Club, 1902, pp. 253-60. 

 X Bull. Internat. Acad. Sci. Cracovie, 1902. pp. 112-30. 

 § Bull. Torr. Bot. Club, xxix. (1902) pp. 170-2. 



