124 



THE AMERICAN MONTHLY 



[May, 



Cell cultures were made in order to observe with the microscope 

 the different phases in germination of the spores and growth of 

 the fungus. Liquid agar containing a dilution of spores from one 

 of the culture-tubes was poured upon a sterilized cover-glass, 

 which was then inverted on the ring of the cell. Figure 3, a, 

 represents some of the spores in the cell culture. They are oblong, 

 usually pointed at one end, nearly cylindrical, and either straight 

 or slightly curved. The appearance of the contents of the spores 

 varies. Sometimes the protoplasm is nearly homogeneous, with 

 one or more vacuoles, or it may be finely granular, with no 



vacuoles or quite 

 coarse granules 

 maybe irregular- 

 ly distributed in 

 the homogeneous 

 protoplasm. The 

 latter condition is 

 a very common 

 one before ger- 

 mination, and the 

 behavior of these 

 granules has sug- 

 gested that pos- 

 sibly they may be 

 stored products 

 to be used during 

 the process of 

 germination and 

 the early growth 

 of the mycelium. 

 It does not seem 

 there could be 

 any need of such stored products for spores in artificial cultures 

 where the spore lies in a rich nutrient media. But they might 

 serve the spores a good purpose in natural conditions where the 

 spore lies upon the surface of the plant and must often produce 

 considerable growth of mycelium before the thread reaches 

 nutritive tissues. 



In germination one or more germ tubes arise from the spore, 

 usually at one side of the ends. Figure 3, b and c represent dif- 

 ferent stages in germination. The coarse granules are quite nu- 

 merous, and in d some of them have moved out into the form- 

 ing mycelium. Figure 3, e represents a farther development of 

 mycelium, and also a farther distribution of the granules in the 

 threads. 



Figure 4, a, <3, and c are three camera-lucida sketches of the 

 growth from a spore which was sown December 14th, at 12.35 

 P. M. a represents the growth which had taken place inexactly 

 24 hours, being sketched at 12.35 P. M., Dec. 15th. b was 



GERMINATION AND GROWTH OF MYCELIUM. 



