324 SUMMARY OF CURRENT RESEARCHES RELATING TO 



confusion as to the identity of several related species. C. L. Shear, 

 Neil E. Stevens and Ruby J. Tiller now publish a thorough study of 

 the whole group. There are seven such species, most of them parasitic, 

 both in the pycnidial and perithecial stages, and several of them 

 described long ago as Sphseria gyrosa. The author gives an exhaustive 

 list of the synonymy of each species. 



The mycelium of Eiidothia jmrasitica is remarkable in that it spreads 

 in a yellow or buff fan-shaped formation in the bark and cambium of 

 the host. The host-cells at the edges of the fan are disintegrated and 

 form a distinct gelatinous band which suggests toxic or enzymatic action 

 upon the host-cells, probably before they are invaded. Towards the 

 outside, stromata are developed which finally rupture the epidermis, 

 and in these are embedded the pycnidia and perithecia. The stroma of 

 all the species is yellow to reddish in colour. 



Endothia gyrosa they consider to be the type of the genus which is 

 divided into two sections chiefly by the character of the ascospores ; 

 there are no paraphyses present. Cultures of the different species were 

 made ; they grew equally well in light or darkness. 



Endothia parasitica, the most actively parasitic of all the species, has 

 been found on Acer, Carya, Castanea, Quercus and Rhus, but at present is 

 only known as a serious parasite on Castanea, and on American chestnuts 

 is actively parasitic under all the conditions of soil and climate observed. 

 Oriental species of Castanea are more or less resistant to the disease, 

 both in America and their native homes. 



Spore Germination in Onygena equina.* — It had been found by 

 Marshall Ward and others that the spores of species of Onyyena would 

 not germinate until they were treated with gastric juice. W. Brierley 

 has made exhaustive cultural experiments of the various reproductive 

 bodies of 0. equina, and he finds tliat the ripe ascospores will germinate 

 after a prolonged resting period ; a vigorous growth was obtained from 

 such spores in glue and gelatin (only a few germ tubes in water). 

 They develop after a much abbreviated resting-time when treated with 

 gastric juice. Unripe ascospores and chlamydospores germinated 

 immediately in suitable solutions in the absence of digestive treatment. 



Plectodiscella veneta.f — W. H. Burkholder, while studying the 

 anthracnose of the raspberry caused by Glceosporium veneta, found, as a 

 further growth on the stroma of the Glmosporium, an ascigerous form 

 consisting of a stroma-like body, very small and pulvinate ; the tissue of 

 the structure is plectenchymatous, the outer layer composed of thick- 

 walled brown cells, this layer splitting apart as the stroma matures. 

 The asci are scattered irregularly through the fungus tissue ; there is no 

 differentiated hymenium. Burkholder recognized its affinity with 

 Plectodiscella Piri, an epiphytic fungus. Inoculation experiments from 

 the ascospores repi'oduced the Glmosporium stage. 



♦ Ann. Bot., xxxi. (1917) pp. 127-32. 



t Phytopathology, vii. (1917) pp. 83-91 (3 figs.). 



