WINGE, CYTOLOG. STUDIES IN THE PLASMODIOPHORACE^. 15 



and TisoN^^ have transferred the fungus from Sorosphaeray 

 where Schwartz had placed it, to their new genus Ligniera. 



Lignieni Graminis (Schwartz) Winge comb. nov. 



This Plasmodiophoracea, described by Schwartz-^ in 1911, 

 must like Sorosphaera Jiinci be transferred to the genus 

 Ligniera, as according to the author it does not produce 

 hypertrophy. The fungus was found in roots of Poa annua 

 and other grasses and most often in tumours on roots at- 

 tacked by eel-worm, the swellings were never due to the 

 fungus. Also in this species the author has found amoebae 

 in root-hairs and he states: »doubtless it is the usual method 

 by which the members of the Plasmodiophoraceae enter their 

 host-plant». — Schwartz did not succeed in infecting sound 

 Poa annua plants. 



Sorodiscus Callitrichis Lagerh. et Winge gen. nov. et 



sp. nov. 



We shall now proceed to describe a new Plasmodio- 

 phoracea which has already been mentioned a couple of times 

 in the literature and of which even illustrations have ap- 

 peared. 



Kareltschikofe and Rosanoff^^ (1870) give a detailed 

 description of the fungus and figure on a plate what they 

 see. They mention destruction of the host-plant, Callitriche 

 aiUumnalis, and state, that the fibro-vasal strings which 

 normally occupy the centre of the stalk-axis in the infected 

 organs move out into the cortical tissue. In the tubers the 

 cells become elongated in a radial direction and between 

 them are seen large spaces which are strongly developed 

 intercellulars. As regards the fungus itself they mention 

 that in the cells are seen peculiar, flat, plate-formed bodies 

 of constant thickness, but of very varying outline, as they 

 adapt themselves to the shape of the host-cells. The plates 

 consist of very small polj^gonal cells, arranged in two layers 

 and forming a parenchymatic tissue. These formations con- 

 tain in the cell-wall a considerable amount of silica. Karel- 

 tschikoff looked upon these spore-aggregations as cystoliths 



