GERMINATION AND GROWTH. 149 



leaving the portion nearest to the parent cell colourless and 

 lifeless. When nearly attaining their ultimate dimensions, all 

 the tubes are divided towards their outer extremity by transverse 

 septa into unequal cells ; then simple and solitary processes, of 

 variable length and form, but attenuated upwards, proceed from 

 each segment of the initial tube, and produce at their extremity 

 an oval spore (teleutospore, Tul.), which is slightly curved and 

 unilocular. These spores absorb all the orange endochrome from 

 the original tubes. They appear in immense numbers on the 

 surface of the fungus, and when detached from their spicules 

 fall upon the ground or on any object which may be beneath 

 them. So freely are they deposited that they may be collected 

 on paper, or a slip of glass, like a fine gold-coloured powder. 

 Again, these secondary spores (teleutospores) are capable of 

 germination, and many of them will be found to have germinated 

 on the surface of the Podisoma whence they originated. The 

 germ filament which they produce springs habitually from the 

 side, at a short distance from the hilum, which indicates the 

 point of attachment to the original spicule. These filaments 

 will attain to from fifteen to twenty times the diameter of the 

 spore in length before branching, and are in themselves exceed- 

 ingly delicate. The tubes which issue from the primary spores 

 (protospores, Tnl.) are not always simple, but sometimes forked ; 

 and the cells which are ultimately formed at their extremities, 

 though producing filiform processes, do not always generate 

 secondary spores (teleutospores) at their apices. This mode of 

 germination, it will be seen, resembles greatly that which takes 

 place in Puccinia. 



The germination of the Ustilagines was in part examined by 

 Tulasne, but since has received accessions through the labours 

 of Dr. A. Fischer von Waldheixn.* Nothing, however, of any 

 importance is added to our knowledge of the germination of 

 Tilletia, which was made known as early as 1847. t After some 



* Von Waldheim, on the " Development of the Ustilaginese," in " Pringsheim's 

 Jahrbucher," vol. vii. (1869) ; translated in " Transactions of N. Y. State 

 Agricultural Society for 1870." 



t Berkeley, on the "Propagation of Bunt," in "Trans. Hort. Soc- London," 



