THE NAME OF THE FUNGUS. 25 



manner as the conidia, and the description given for the germination 

 of the conidia will hold for the ascospores. 



Conidia were found in the bitter-rot canker during- the summer of 

 1902, and in the latter part of 1902 perithecia and asci were found in 

 the canker. (Science, 17: 188, 1903.) The description of these will be 

 given below in discussing the cankers. 



The bitter-rot fungus grows readily on most culture media. It grows 

 vigorously on apple agar, on sterilized apple wood or leaves, on sterile 

 pine blocks, bean stems, etc. It is in many respects a true saprophyte. 

 It is questionable whether it ought to be considered a parasite at all 

 times when growing on the ripe fruit in the orchard, for at the time it 

 attacks such fruit the latter is practically full grown and is no longer 

 composed of cells or tissues which will react when stimulated. The 

 fungus develops best at temperatures ranging from 33° to 38° C. 

 (91.1° to 100.1° F.). Apples which were kept in incubators at 38° C. 

 after infection showed decayed spots 1 inch in diameter in from 

 one to three da} T s. Cold checks growth materially, and at 2° C. or 

 35.6° F. (cold-storage temperature) no further growth takes place. 



THE NAME OF THE BITTER-ROT FUNGUS. 



About the middle of the last century a number of funo-i were 

 described by M. J. Berkeley as growing on various fruits and bring- 

 ing about their decay. In 1851 he published the discovery of a fungus 

 growing on grapes which caused ripe rot. He says of this: 



The surface of the spots is rough, with little, raised, orbicular, reddish bodies 

 arranged in concentric circles and easily separating from the matrix, which is per- 

 forated for their protrusion. The outer surface of these bodies consists of delicate 

 cells, with a distinct darker nucleus, and when this is removed a lobed hymenium 

 is seen within, rough, with distinct sporophores, each of which is surmounted by an 

 oblong spore, sometimes constricted in the center, and occasionally so much so as to 

 become pyriform, and varying in size from y^Vo to t |q- inch. In age the perithecia 

 fall away, leaving a little aperture, the border of which is often stained with black. 



Berkeley named this fungus Septoria rufo-maculans, n. sp. He fig- 

 ures pycnidia and spores, and for reference the latter are reproduced 

 herewith (tig. 1). In 1860 he changed the name to Ascochyta rufo- 

 maculans. Yon Thumen (1879) renamed this grape fungus Glceosporium 

 rufo-maculans (Berk.) v. Th. 



In 1850 Berkeley described a fruit-rotting fungus growing on apples, 

 which he called Glososporium fructigenum, n. sp. This is the first 

 authentic description of a fungus causing bitter rot, or ripe rot, of 

 apples. Berkeley says of this fungus: 



On examination each plant was found to consist of a branched inosculating myce- 

 lium, giving rise to simple or forked subfastigiate irregular threads, each tip of which 

 was surmounted by an oblong, curved, or irregular spore about ,,',„ of an inch in 

 length. There was not the slightest trace of an investing membrane or perithecium. 



