122 i«a-^^ V 7*-)i/A,-b |--x^]V^-0^.?fii:^@t3=H^flM't^^^#l-s*^'^ 



duced in tlie culture-media I have used, while the chlamydospore production is 

 generally conspicuous. On the soy agar and apricot-decoction agar media, the 

 aerial growth of the mycelium is comparatively vigorous, and there is at the same 

 time some growtii in the substrata. The characters on different media are as 

 follows : 



a. Ciihiires on the Icaf-decottion agar of Lupinus polyphylhis. The mycelium begins to spread from 

 the infected portion at first as a white or li;;ht brown weft aiul spreads rapidly toward the ed.;e. The 

 mycelium is apt to creep on the surface of the medium, and the aerial mycelium is very scanty. The my- 

 celium turns [gradually hrown in color. After a while, numerous small black dots are seen in the peripher- 

 al portion of the medium, where the creeping mycelium is thinly formed. Under a microscope, I have prov- 

 ed those dots to be the knots of chlamydospores. The conidiospores are rarely produced in old cultures. 



b. Cultures on the corn-tneal agar. The mycelial .growth on the surface of this medium is sometimes 

 entirely lacking or very scant. T!ie mycelium grows entirely in the medium and it presents macroscopical- 

 ly as dense radi.ating groups of many grayish-black hue stripes or lines. On these stripes or lines are found 

 iiumerou.s black spots, which are tlie knots of the clilamydospores. The conidial productioii is, however, 

 very scant. 



c. CuUtires on the apricot-decoction agar. On this medium, the fun.^;us grows vigorously aad caused 

 it to become more or less darkened. At first a white aerial mycelium grows actively and after a while its 

 color gradually turns gray and sometimes blackish gray. Tlie knots of the chlamydospores are alf.o more 

 or less produced on the hyphae growing in and on the medium. 



d. Cultures on the soy agar. The use of the Japanese soy or shoyu as a cultural medium for fungi was 

 at first proposed by Prof. M. MiyoshiC''-"^ in 1895. On this medium, a velvet-like I)ro\vnish-gray mycelial 

 layer is produced within a week after inoculation. The chlamydospores are produced al)Uiulantly. The 

 conidiospore is not produced even on the medium of two months old. 



7. Chlamydospores of the Causal Fungus 



The chlamydo.spores are most abundantly produced in the corn-meal agar 

 cultures, although in other cultures they are also formed to more or less extent. 

 The hyphae, from which the chlamydospores are to be formed, turn gradually 

 brown or light brownish gray in color, accompanied by the process of the divi- 

 sion into a series of numerous short ellipsoidal cells. These cells transform at 

 once into the chlamydospores first by their swelling and then by the thickening 

 of their cell-walls. Consequently the chlamydospores thus formed are usually 

 arranged in a chain, although a single chlamydo.spore is rarely produced inter- 

 calarely in the hyphae. Our fungus is, however, characterized by the formation 

 of the knots of the chlamydo-spores, having remarkable forms. A knot of the 

 chlamydo-spores consi.sts of a mass composed of from a few to thirt)' cells having 

 a thick and deep brownish-black cell-wall and granular contents. The knots 



