104 TECHNICAL BULLETIN 4. 



By this method it has been possible to bring to germination most spores which 

 otherwise would not germinate. The length of time required to bring about ger- 

 mination varies greatly. The spores of some species usually germinate after a 

 few months, others after a half or an entire year, others require several years be- 

 fore germination, some even five years. ... In this methodical way, which is, to 

 be sure, nothing but an imitation of what takes place in nature, ultimately all 

 spores can be induced to germinate. Therefore it can be scientifically proved that 

 the earlier or later germination is only an adaptation, a resting period, which under 

 the natural conditions must be passed through, if the inner and apparently chemical 

 changes are to operate, through which the germination of the spores is slowly pre- 

 pared and finally made possible. 



In this way Brefeld was able to germinate the spores of the following 

 species none of which would germinate v/hen fiist mature (length of time 

 in moist earth given after each): Anlhracoidea {Ustilago) Caryces Bref., 

 overwinter; Anlhracoidea subindvsa BreL, 1 year; Doassansia Alismatis 

 Nees, 1 year; D. Limosellae'Kunze, 1 year; D. punctiformis Niesse, more 

 than a year; D. Sagdlariae Fckl., over winter; Melanotaenium cingeus 

 Bref., 4 years; Neovossia Barclayana Bref., 2 j^ears; SpJiacelotheca Hydro- 

 piperis Schum., 6 months; Tillciia controversa Kiihn, 2 years; Tilleiia 

 decipiens Pers., 3 years; Tolyposporium bullatum Schroei., 9 months; 

 Tol. Junci Schroet., 6 months; Tol. Penicillariae Bref., 1 year; Urocystis 

 Anemones Pers., 6 months; Ur. Filipendidae Tul., 1 year; Ustilago Adoxae 

 Bref., 1 year; U. anomola Kunze, over winter; U. Bistortanim D. C, 1 

 year; C/. Cora's Bref., 2 years; U. domesticaBvei., Q months; U.Holostei 

 D., 3 years; U. utricxdosa Nees. Other ^^Titers also have found that for 

 various species, a weathering under natural conditions was necessarj' iu 

 order to secure germination. 



Substitution of Nutritive Solution for Weathering Period. — In the case 

 of some species Brefeld believes that the same changes which are ordinarily 

 induced by storage in damp soil for a long period may be induced at once 

 by the use of his "nahrlosung." For example, he finds that the corn 

 smut spores when first mature will not germinate in water, but if kept until 

 the following spring they germinate in water. If, however, the freshly 

 matured spores are put in nutritive solution, they germinate overnight 

 almost without exception. He concludes, therefore, that the changes 

 induced by one are the same as those induced by the other, or, in other 

 words, that each may be substituted for the other. 



Freezing. — Wliether or not freezing has any influence on germination 

 seems never to have been determined. Brefeld makes no mention of freez- 

 ing, and one infers from his publications that his buried spores were never 

 frozen. Since the spores of practically all species of smuts have been suc- 

 cessfull.y germinated without freezing, it may be safely said that freezing 

 is not a necessary condition of the ])rocess. 



Essential Conditions for Germination of Urocystis cepulae Spores. 

 Search through all available literature on the subject revealed only one 

 reference to previous attempts at germination of the spores. Thaxter (18) 

 was unable to germinate fresh spores either in water or in moist air. When, 



