410 Agricultural Experiment Station, Ithaca, N. Y. 



the mycelium. These resemble the stroma at the base of the 

 pustules on the stem, but in the artificial cultures do not seem to 

 be especially concerned in the production of basidia and spores, 

 since but a few are developed in connection with them. 



Numeroiis basidia and spores are producwl, however, all alonj^ 

 the threads and a uiass of thein at the point of inoculation. In 

 a few days more luany fungus threads arise above the agar and 

 ])roduce a fluffy white growth uiK)n the surface, nearly obscuring 

 the black points. 



No pigment was noticeable in these cultures. New cultures 

 were then started by tmns]>lanting portions of agar the size of a. 

 small pea with a mat of niycelinni and spoi'es to fresh cultiin^ 

 tubes. In the fi'esh agar the gi-oA\ th took place in the same man- 

 ner as in the tii-st tubes, but upon the surface of the transplanted 

 jwrtions a faint, pink pigment appeared, similar to that dev<'loped 

 in some si)ecies of rxloeospoi'ium and r/olh^oinehnnL 



Cell cultures were made in order to observe with the microscope 

 the different ])hases in gei-niination of the spores and growth of 

 the fnngns. Li(pii(l agai- containing a dilution of spoi'cs from one 

 of the culture tubes was ponrr^d njuni a st<'rilized cover glass 

 which was then inverie^d on (he ring of the cell. Fig. '^, a, 

 represents some of the sjwres in the cell cultiiiM'. They are oblong, 

 usually pointi'd at one end, nearly cylindrical, and either straight 

 or slightly curved. Th<' a])pearance of the contents of the spores 

 varies. Sometimes tlu^ proto]»lasni is nearly homogemNms 

 with one oi' more vacuoles, or it may l)e finely granular, with 

 no vacuoles, or (piite coarse granules may be iiregularly distri- 

 butee! in the homogeneous i>i"f>toplasm. The latter C{)nditJon is 

 a very common one Ix^fore gennination, and the b<,4iavior of 

 these granules has suggest<^ that ]»osisibly they may be vstored 

 products to be used dunng the ]>rocess of geaanination and tlie 

 early gT'owth of the mycelium. It' does not seem there could Ix 

 any need of snch stored jyroducts for spores in artificial cultiii"e« 

 where the vspores lies In a rich nutrient media. But they might 

 serve the spores a good purpose in natural conditions where the 

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



