SPOROBOLOMYCES 201 



laria and allied genera, but, Brefeld x expressly states that these 

 conidia, along with their conidiophores, are produced only under the 

 surface of liquids. In C rater ellus cerasi, Tremella lutescens, etc., 

 the production of the basidial fruit-body is preceded by the produc- 

 tion of a conidial fruit-body on which the conidiophores are branched 

 and bear numerous clustered conidia projecting into the air. These 

 conidia, as illustrated by Brefeld, 2 have not the form of basidiospores 

 and are not borne singly on conical sterigmata ; and, from Brefeld's 

 account of their development and fate, there is no reason to suppose 

 that they are violently discharged into the air. 



The so-called secondary spores of the Hymenomycetes (observed 

 in Auricularia mesenterica, 3 Platygloea nigricans* etc.) and of the 

 Uredineae (observed in Puccinia Malvacearum, 5 Gymnosporangium 

 Sabinae, 6 Cronartium ribicola, 7 etc.) arise in the following manner. 

 A basidiospore, which has fallen on to the surface of a moist 

 substratum that is defective in nutrient substances, instead of 

 putting out a germ-tube, develops a sterigma which projects into 

 the air and forms at its apex a spore which exactly resembles in form 

 the original basidiospore. It is this new spore which is known as a 

 secondary spore . During secondary-spore formation , the protoplasm 

 of the original basidiospore is transferred to the secondary spore, so 

 that, in the end, the basidiospore becomes completely exhausted of 

 its contents. Presumably, secondary spores, when well formed, are 

 shot away from their sterigmata by the drop-excretion mechanism. 



1 0. Brefeld, Untersvchungen iiber Pilze, Heft VII, 1888, p. 75. 



2 Ibid., Taf. VI, Figs. 13-17 ; Taf. VII, Figs. 1 and 4. 



3 Ibid., Taf. IV, Fig. 10 ; Sappin-Trouffy (Le Botaniste, Ser. 5, 1896, p. 56, 

 Fig. 5) gives an illustration of a secondary spore of Auricularia auricula- Judae. 



4 Ibid., Taf. IV, Fig. 14. Brefeld's Tachaphantium tiliae = Platygloea nigricans. 

 In addition to the Hymenomycetes mentioned in the text above, Brefeld observed 

 and illustrated the formation of secondary spores in Exidia guttata (Heft VII, Taf. V, 

 Fig. 13), Sebacina incrustans (Heft VII, Taf. VI, Fig. 26), Pachysterigma ( = Tulas- 

 nella) incarnatum (Heft VIII, Taf. I, Fig. 1), P. fugax (same plate, Fig. 4) and 

 Radulum laetum (Heft VIII, Taf. II, Fig. 2). 



5 Sappin-Trouffy, " Recherches mycologiques," Le Botaniste, Ser. 5, 1896, p. 118, 

 Fig. 30, g, h. 



6 Ibid., p. 125, Fig. 33, k. 



7 R. H. Colley, " Parasitism, Morphology, and Cytology of Cronartium ribicola," 

 Journal of Agricultural Research, Washington, Vol. XV, 1918, p. 638, also Plate LVII, 

 CC and DD (Reproduction of DD in Gaumann's Vergl. Morph. der Pilze on p. 439). 



