512 BRITISH FUNGI 



colour, the lower part black, 1-2 in. long, rather slender. The 

 ascophores spring from thick black, prostrate, very irregular 

 branches or sclerotia, which are imbedded in the soil. 



The ascophores are wrinkled and often crooked. The sclerotia 

 are very abundant and develop rapidly. I have seen a barrow-load 

 of sclerotia removed from a cucumber frame, the growth of a single 

 season. 



Among soil in cucumber and melon frames, mushroom beds, etc. 



PORONIA 



Ascophore discoid, flattened, stalked, substance between fleshy 

 and corky ; perithecia immersed, their mouths opening on the 

 flattened upper surface of the ascophore (spores elliptical, i-celled, 

 coloured). 



Cannot be confused with any other genus on account of the 

 peculiar form of the ascophore, which resembles a large flat-headed 

 nail, the under surface running gradually down into the somewhat 

 slender stem. 



P. punctata. — Ascophore stipitate, upper surface flat, circular in 

 outline, whitish, dotted with the black mouths of the perithecia, 

 \~'l in. across, gradually narrowing downwards into the stem, 

 blackish below, J-i in. high. 



On dry horse and cow dung. Rare. 



CORDYCEPS 



Ascophore vertical, clavate or subglobose, stipitate (spores 

 needle-shaped, many-celled, colourless). Parasitic on insects. 



A very interesting genus of fungi, some of which will be likely 

 to be mistaken for species of Clavaria by the beginner. All are 

 parasitic on insects, and infection usually takes place during the 

 caterpillar stage, when the spores are either swallowed along with 

 the food plant or enter the body through the spiracles. After in- 

 fection the caterpillar continues to live for some time, and usually 

 passes into the chrysalis condition, when it is killed by the mycelium 

 of the fungus, which usually converts the entire substance of the 

 chrysalis into a dense weft of cork-like substance, the skin of the 

 chrysalis remaining intact. In other instances the insect is killed 

 during the caterpillar stage. As a rule, two distinct forms of re- 

 productive bodies, a conidial stage, followed by an ascigerous or 

 more highly evolved condition, are produced. After the caterpillar 

 or chrysalis, as the case may be, has been dead for some time, the 

 conidial form of fruit is formed, which usually consists of a more 

 or less feathery, branched tuft of silky-looking mycelium, | in. or 

 more in height, which is powdered with the very minute conidia. 

 Eventually the conidial form of reproduction entirely disappears, 

 and is followed in due course by the ascigerous form, wliich. as 



