CONTRIBUTIONS FROM THE WiSLEY LABORATORY. 



543 



further spread of the disease occurred. The grower appeared satis- 

 fied that the amount of moisture about on the plants and in the 

 atmosphere was the predisposing cause of the trouble, for he deter- 

 mined henceforth to adopt a system of sub-irrigation in his houses. 



There is little doubt that moist conditions and lack of ventilation 

 would conduce to the spread of such a disease as this, and the main 

 preventive measures would be attention to these details. 



As the fungus is new to Britain, and is here recorded for the first 

 time, a technical description is given. 



Marssonia Panattoniana, Berlese in Eiv. Patol. Veget. III. 

 (1895), p. 342. 



~Marso7iia* Panattojiiana, I.e.; Sacc. Syll. xvi. p. 1021; &c. 



= ? M. perforans Ell. and Everh., U.S.A. Exp. Stn., Ohio, 



Bull. 73 (1897). 

 — Marssofiina Panattoniana (Berl.) P. Magn., Hedw. xlv. 



(1906), p. 89. 



Spots roundish, often confluent, pale with a darker margin, 

 often dropping out, 3 to 5 mm. diameter; spore groups gregarious, 

 at first subcutaneous, later liberated by the destruction of the 

 epidermis; conidia obclavate, 11 to 20 x 3 to 4 n, one septate 

 across the middle, hyaline, granular; basidia short. 



2. Leaf-spot of Campanula. 



In December 1911, some leaves of Campanula persicifolia were sent 

 from his garden at Old Colwall by Mr. E. Ballard. The leaves had 

 greenish-brown, circular or sub-circular, dead or dying spots up to 

 half an inch in diameter (but usually somewhat smaller), margined 

 vvith purplish-brown scattered over them. 



Microscopic examination showed the presence of a fungus, the 

 nycelium of which permeated the tissues of the spots, and produced 

 small tufts of fruiting branches which issued through the stomal 

 Dpenings. These tufts are whitish in appearance, and may be made 

 )ut by careful search with a pocket lens. Each consists of several 

 colourless, erect, rather crooked branches, and each branch bears at its 

 ipex a colourless two- or three-celled spore. The fungus is clearly a 

 species of Piam.ularia, differing from most of its genus, however, at 

 east so far as the present examples go, in the absence of denticulations 

 it the apex of the conidiophores. 



There is no record of the occurrence of a species of Ramularia 

 Attacking any Campanula in this country, but several other forms are 

 blown, including R. variabilis on foxgloves and mulleins, it!, geranii 

 pn various species of Geranium, R. kellehori on Helleborus foetidiis 

 md H. viridis, and R. vallisumbrosae on Naroissus poeticus, as well as 

 riany others of less importance in horticulture. 



* The generic name was spelt by Berlese and others ' Marsonia,' but 

 l^'iscHER, who •established the genus [Rabenhorst, Fungi Europ. Exsicc, 

 lHo. 1857 (1874)] wrote the name Marssonia, naming the genus after Marsson. 



