642 STATE BOARD OF AGRICULTURE. 



like a chain. This condition appeared in all the media at the end of 

 twenty-four hours. At the end of 36 hours the end cells of the spores 

 had grown somewhat irregular, slightly tapering, and somewhat nar- 

 rower than the middle cells. The elongation of both ends of the spore 

 preceding the formation of definite germ tubes was of general occur- 

 rence (Plate 9, Fig. 3). Exceptions to this were seen when the number 

 of spores in the hanging drops was increased so that the spores touched. 



After 48 hours, germ tubes were formed varying from 1 to 4 for each 

 spore. The germ tube may grow from any cell. (Plate 9, Figs. 1 and 2). 



One may consider the germination of the spores as beginning either 

 with the formation of the definite germ tube or with the growth from 

 the terminal cells. In many spores instead of developing germ tubes 

 immediately, the terminal cells elongate and then branch. The other 

 cells in the spore may or may not send out germ tubes. For the first 

 four days, the germination phenomena and initial colony formation are 

 much alike in various media (Plate 9, Figs. 4 and 5). With the subse- 

 quent growth, differentiation takes place. 



In the Van Tieghem rings with nutrient glucose agar and potato glu- 

 cose agar a very luxuriant growth took place. The four-day-old colonies 

 were readily visible to the unaided eye. The hyphae were richly branch- 

 ed, with prominent oil drops, and were very striking because of their 

 irregular contour. (Plate 9, Fig. 7, Plate 8, Fig. 5). After six days, the 

 medium became brown, and after eleven days, the mat-like stroma was 

 so thick that observation with a microscope was impossible. 



In distilled water the ring cultures made but slight growth other than 

 germination and no sporulation was seen. 



Cornmeal agar and tomato-leaf agar gave a moderate growth in mark- 

 ed contrast to the media rich in sugars. After four days, secondary 

 si)ores — long filiform structures arising from small papillae on the my- 

 celium — were found in tomato-leaf agar and two days later in the corn- 

 meal agar. After eleven days, some of the threads of mycelium became 

 dense brown. (Plate 9, Fig. 6). This condition was found in both corn- 

 meal and tomato-leaf agar. (Plate 8, Fig. 4). Pycnidium formation was 

 noticeable after the eleventh day. (Plate 9, Fig. 8). 



In nutrient broth cultures, a diffuse rapid growth took place. The 

 hyphae were narrow and regular, and were not profusely branched. On 

 the sixth day, secondary spores were found. Five days after formation 

 it was found that these secondary spores had germinated forming new 

 colonies. (Plate 8, Fig. 3). Others produced secondary spores imme- 

 diately after elongation (Plate 8, Fig. 2). After eleven days pycnidium 

 formation was evident throughout the culture. 



The observations may be summarized as follows: 



1. Spore structures, evidently secondary spores, are formed abund- 

 antly in various media. These may germinate and form new colonies. 

 This contradicts Delacroix (1900) who states, ''The stylospores germin- 

 ate easily in water and nutritive liquids by the production of a septate, 

 branching filament imthout the formation of secondary spores."^ 



2. The jjresence of a distinct type of mycelium; whether this mycel- 

 ium is a special stroma or pycnidial mycelium has not been definitely de- 



"As the nutritive liquids used were not mentioned, repetition of Delacroix's experiment was 

 not possible. 



