Germination of Telentospores of Ustilagineo'. 75 



of De Bary, this germ-tube constitutes the promyceHum. 

 In the course of a few hours the promyceHum has received 

 into itself all the protoplasm originally contained in the 

 spore. Transverse septa now make their appearance in it, 

 and it thus becomes divided into four or five equal compart- 

 ments. From the outer walls of the now septate promy- 

 celial tube little offshoots or buds arise, into which the 

 protoplasm of the tube passes (Plate VII. Fig. i). These 

 buds continue to increase in size until they become elon- 

 gated, ovate, or elliptical promycelial spores ; they then 

 fall off. Generally they are produced from the side wall 

 of the promycelium, near the septa, and almost always one 

 is produced from the apex of this structure. If the proto- 

 plasm in each segment be exhausted by the production of 

 promycelial spores, then spore-formation from it ceases ; 

 but if all the protoplasm be not used up in the formation 

 of the first promycelial spore, a second but usually a smaller 

 one is budded off. In fact, spore-development from the 

 promycelium goes on until its protoplasmic contents are 

 exhausted. It is not at all uncommon for one of these 

 primary promycelial spores to remain attached to the pro- 

 mycelium instead of falling off, and at its free end to give 

 off a small bud, which gradually grows into a secondary 

 promycelial spore, the latter being of smaller dimensions 

 than the one from which it sprang (Plate VII. Fig. 2). These 

 primary and secondary promycelial spores, after they have 

 fallen away from the promycelium, show still further 

 developmental changes in water, (i) They may, as Tulasnc 

 has figured, emit a germ-tube (Fig. 12) — a very narrow 

 tube pointed at its extremity, into which the contents of 

 the promycelial spore are passed.* (2) Two promycelial 

 spores, being near one another, may become joined by a 

 transverse branch, through which the contents of one of 

 * Tulasnc, "2'' Memoire," pi. I2, figs. 22-24. 



