i84 



RESEARCHES ON FUNGI 



Abnormal drop-excretion like that shown in Fig. 91 occurs in 

 the Hymenomycetes, 1 the Uredineae, 2 and Tilletia (Fig. 118, 

 p. 243), and this fact goes far to strengthen the view that the 

 mechanism of spore-discharge in Sporobolomyces is identical with 

 the mechanism of basidiospore-discharge in the Basidiomycetes in 



general. 



The Successive Production of Spores on One and the Same 

 Sterigma. — A yeast cell of Sporobolomyces roseus, which was filled 



F IG . 91. Sporobolomyces roseus. Abnormal excretion of a very large drop of fluid 



from the spore-hilum and non-discharge of the spore. At a, lateral view of a 

 yeast cell on agar, which has produced a sterigma and a spore ; the spore is 

 mature. At b, a drop of normal size has just been excreted from the spore- 

 hilum ; the spore and drop should now be discharged, but are not. At c, the 

 drop has grown beyond the usual size and has ascended on to the spore. At d, 

 the drop has increased in size to such a degree that it now forms a spherical 

 globule which encloses and hides the spore and is larger than the whole yeast 

 plant. The spore was not discharged. Drawn by A. H. R. Buller and Ruth 

 Macrae. Magnification, 1866. 



with protoplasm, was watched as it developed its sterigma and spore 

 (cf. Fig. 90, nos. 1-8). During this process it became somewhat 

 vacuolated ; but, at the moment when the spore was violently 

 discharged, a considerable amount of protoplasm was still left in the 

 parent cell. The parent cell, after the discharge of the spore, was 

 kept under continuous observation. Its vacuoles were seen to 

 decrease in size, doubtless in consequence of new protoplasm being 



1 Vide these Researches : for Psalliota campestris, Vol. II, Fig. 8 (p. 18) ; for 

 Panaeolus campanulatus, Vol. II, Fig. 104 (p. 308) ; and for Coprinus sterquilinus, 

 Vol. Ill, Fig. 106 (p. 250). 



2 Vide these Researches : for Puccinia graminis, Vol. Ill, Fig. 205, A (p. 508). 



