36 TELEUTOSPOBES 



In the formation of teleutospores in the higher [Jredinales, 

 the spore-mother-cell first divides into an upper fertile cell and 

 a lower sterile cell, which elongates more or less to form the 

 pedicel. The upper cell may remain undivided, or may divide 

 again : the lower of these two may then continue to divide and 

 so on, to form a many-celled chain. When the chain is long, as 

 in Xenodochus, it is seen very clearly that the spores are formed 

 like a^cidiospores to this extent that the uppermosl is always 

 the mosl mature. This may be taken as a sign that they are 

 modifications of secidiospores to form resting-spores. In Endo- 

 pJiyllum the a-cidiospores previously mentioned germinate as 

 soon as mature with a basidium, and are therefore teleutospores 

 also: this is the primitive state of things from which t he- 

 present wide division of labour into rejuvenating (aecidio-), 

 multiplying (uredo-), and resting (teleuto-) spores has been 

 evolved. 



In some of the lower Uredinales, the teleutospores are 

 termed beneath the cuticle or in the epidermal cells, bu1 the 

 usual position is directly beneath the epidermis. Throughout 

 the whole group the colour of teleutospores is almost uniformly 

 brown, varying in shade from a pale yellowish-brown up to 

 nearly black. Their contents are, like those of uredospoiv>. at 

 first often oily and yellow, afterwards colourless. In the lo\ - 

 genera, those found on Ferns, the teleutospores are quite 

 hyaline. 



Their surface is most often smooth externally, but occasion- 

 ally marked with superficial unevennesses, such as waits, 

 tubercles, lines, stria?, reticulations, and pits; a few have spiny, 

 papillose, or finger-like processes, either at the summit or all 

 round. The majority of them have one pore to each cell, as in 

 Puccinia and Uromyces, covered at times by a distinct, often 

 hyaline, pore-cap; this is the highest type, being furthest 

 removed from the many-pored aecidiospores. Other genera 

 have 2 to 4 germ-pores to each cell, as in Phragmidium and 

 Gymnosporangium. In some cases, as in Uromycladium and 

 Ravenelia, the teleutospores are borne in bunches at the top of 

 a common stalk, either with or without accompanying hyaline 

 cysts, i.e. abortive spores. An approach to this is found in the 



