82 BOTANICAL GAZETTE. 



central, but more largely in the superficial parts of the preparation. 

 The mode of formation of these spore masses is strikingly suggest- 

 ive of other Carposporece. Essentially it consists in one or two" end 

 cells from the same or different threads becoming bladder-like [and 

 contents dividing into spore masses?], whilst around these, delicate 

 filaments spin themselves so quickly and closely that whafc : trans* 

 pires in the center can only be conjectured. This outer krt'dt-like 

 protecting case appears from the figures to be more or less com- 

 pletely absorbed or reduced by the growth and pressure of .the spore 

 masses. 



Examining these affected Trientalis plants in the cold wet 

 weather of autumn it will be discovered that the dark-brown spore 

 masses show signs of growth. Placing these under a microscope 

 and keeping them in a moist atmosphere one may see the individual 

 spores sending out transparent thickish promycelia as growing 

 tubes. Each of these tubes terminates in a basidial cell, which m 

 turn produces 4 to 8 "primary sporidia." The use of the term 

 sporidia in this sense is according to Tulasne. (The sainQ word it 

 is to be observed is used by our American botanists more frequent- 

 ly for the spore-like bodies found in asci of the Ascomycetous fungi .) 



See plate III, figures 1-12. Between pairs of these "primary 

 sporidia" copulation occurs at the base laterally, rarely at the sum- 

 mit. It appears that from these "primary sporidia" secondary ones 

 may be produced directly', with or without a previous copulation. 

 After the fall of the "sporidia," the basidia which supported them 

 may give rise to delicate colorless threads. From the secondary 

 sporidia tertiary ones may be produced and copulation occur betvr 

 them. Or a sporidium may produce another sporidium on one side 

 mid on the other a growing tube. Not only two. but three or more 

 primary sporidia may copulate and then may each produce second- 

 ary sporidia ; or a single sporidium which has not copulated may 

 produce even three successive generations of sporidia. Evident!}* if 

 this copulation, so-called, has anything whatever to do with repro- 

 duction or specific perpetuity, it sits very lightly, so far as necessity 

 is concerned. 



In from 15 to 20 days after sowing the conidia of Tuburcinia 

 upon the Trientalis leaf the charasteristic black spots appear. Ob- 

 servation has made it very clear tbat both wind and insect-: by car- 

 rying the conidia aid in infecting plants previously healthy. These 

 conidia, after sending their tubes between the epidermic cells of the 

 host, develop around their point of entry a mycelium mass, each for 

 itself, which remains well divided from those produced by other 

 conidia. This Tuburcinia Trientalis furnishes, not the firsts but the 

 best illustration ofconidial production among the Ustilaginece. 



Tuburcinia has both its conidia and its sporidia on ths same 



ant, as ithor hazards the con- 



that other link-:. found, comparable to those of the 



Uredinece, which will fairly make out another example of heteroe- 



< ism. 



For w -:pace we pass by tin 1 experiments upon Sorospori- 



