En doph) 'I 111 in. 229 



Exsiccati. 

 Berk., 299. Cooke, i. 6; ii. 302. Vize, "Fungi Brit.," (54. 

 " Micro. Fungi Brit.," 458. 



On Euphorbia amygdaloides. 

 April to June. 



Biology — The spores of this species germinate freely in water, and 

 produce a promycelium with three or four promycelial spores. When 

 placed on the cuticle of a leaf of the proper host-plant, these promy- 

 celial spores bore, by means of their germ-tubes, through the epidermal 

 cells and enter the pai'enchyma of the leaf, between the cells of which 

 they soon produce a richly branched and widely extending mycelium. 

 If the entrance has been efifected into an old leaf, the further develop- 

 ment of the parasite ceases when the leaf falls off. The mycelium 

 passes along the petiole and enters the stem, where it may be found, 

 especially in the pith and inner bark. In the following spring, the 

 foliage which is produced by an infected, is different from that which 

 is produced by a healthy plant. The affected plant sends up longer 

 shoots, with shorter and wider leaves, which have a paler g^reen colour 

 than the healthy foliage (De Bary, Neiie Unterstich., 1865, pp. 20, 21). 

 I find that the promycelial spores often send out germ-tubes while 

 still attached to the promycelium. I have always failed in permanently 

 infecting old plants of Euphorbia ; no matter what the age of the leaves 

 may be, in the ensuing spring the foliage has always been healthy. 

 But if a young seedling be infected shortly after it has come up — that 

 is, while not more than a month or two old — the ni} celium produced 

 in its leaves readily gains an entrance into the stem. The foliage, 

 and shoots sent up by it in the following year are pervaded by the 

 perennial mycelium, and produce aecidia abundantly during the spring ; 

 but the late summer and autumn foliage differs little from healthy 

 foliage, excepting that the leaves are somewhat shorter. The next 

 vernal foliage is, however, secidiiferous. The affected plants seldom 

 flower. 



Endophyllum sempervivi. (Alb. and Schw.) 



Mycelium perennial. Spermogonia globose, then conical, yellow. 

 Pseudoperidia scattered, immersed, at first papillreform, open- 

 ing above by a small foramen, then broadly cup-shaped, with 

 whitish edges. Spores subglobose or angular, verrucose, 

 orange, 20-30/A in diameter, sometimes 30/x long. 



