XIL] NEW DISEASE OF GRASS. 67 



on their bodies, and so infect previously untainted 

 districts. 



Towards the end of 1883 Mr. Greenwood Pirn, M.A., 

 F.L.S., and Dr. E. P. Wright, A.M., F.L.S., detected Isaria 

 fuciformis, B., growing in a new position, viz. on grass 

 belonging to a silo at the Albert Model Farm, Glasnevin, 

 Co. Dublin. Mr. Pirn kindly forwarded examples to us, 

 and he soon afterwards published an illustrated account 

 of the discovery in the Gardeners' Chronicle for 22d Decem- 

 ber 1883. Mr. Pirn's examples were remarkable for 

 being infested with a parasitic fungus, and one apparently 

 till now undescribed. The parasite grows on the Isaria, 

 breaks up its tissues, and more or less absorbs its crim- 

 son colour. The parasite is a Saprolegnia allied to S.ferax, 

 Kutz., of the salmon disease, but different in many im- 

 portant characters. 



The new parasite, which may be termed Saprolegnia 

 pliilomukes, W.Sm. (from sapros, decayed ; legnon, a fringe 

 or border ; phileo, I love ; and muJces, a fungus), is illustrated 

 at Fig. 24, enlarged 400 diameters. The circular bodies 

 are sporangia, zoosporangia, or spore -cases of unusually 

 large size, and filled with small motile spores or zoospores. 

 In the largest sporangium illustrated it will be seen that 

 the zoospores are germinating within the sporangium, and 

 protruding their germ tubes through its gelatinous wall. 

 A remarkable character in this parasite is found in the 

 septate or jointed mycelium, an unusual character in the 

 Saprolegniece, in the mycelium carrying numerous conidia, 

 as at AA, and in the sporangia and mycelial threads often 

 becoming confluent, as at B, C. In the Dublin examples, 

 the sporangia were so abundant that all parts of the 

 Isaria threads were covered, they were so crowded together 

 that they took pentagonal and hexagonal instead of cir- 

 cular forms. Many sporangia were sessile, or intercalated 

 in the mycelium, whilst others were shortly stalked. 

 Antheridia (male organs described under the fungus of 

 the potato disease), as at D, were rare : the jointed my- 



