76 British UrediiiecB and UstilaginecE. 



them passes into the other (Fig. ii). When the first pro- 

 mycehal spore has become emptied of its contents, the 

 second emits a tube which may remain as a germ-tube, or, 

 as it becomes full of protoplasm, its end may swell out and 

 form a third spore, (3) At a variable distance from the 

 spore from which it arose a detached spore may form a 

 connection with one of the segments of another promyce- 

 lium ; sometimes as many as three spores may thus become 

 united.* 



Germination, however, does not always occur in the 

 above typical manner, namely, by the development of pro- 

 mycelium and promycelial spores. From some of the 

 largest teleutospores two promycelia are occasionally given 

 off (Fig. 7). More commonly we find that, instead of pro- 

 mycelial spores being produced in the regular manner 

 above indicated, only one or two segments give rise to 

 them. The others send off branches, into which their con- 

 tents are emptied in the same manner as occurred when 

 spores were formed. The free ends of the promycelial 

 branches often come into contact with one another. When 

 this happens they fuse together and become one continuous 

 tube, (i) Thus a tube given off from one of the upper 

 segments may form a connection with one of the lower 

 segments of the same promycelium in the form of a bow 

 (Fig. 4). (2) Two continuous segments may become united 

 by forming what Brefeld calls a buckle-joint. This con- 

 sists of the unequal growth of one side of the promycelium 

 at the level of one of the septa ; as this growing-out con- 

 tinues the promycelium itself becomes bent at an angle, 

 at first obtuse, but eventually acute. A reference to the 

 figures (Plate VII. Figs, 3 and 9) will render this obvious. 

 (3) Promycelia from two different spores may unite by 

 branches in various ways, either by their ends or at any 

 * Brefeld, loc. cit., pp. 54-67, t. ii., iii., figs. 1-17. 



