“BASIDIOSPORES 37 
British Puccinia Pruni-spinosae and other species, where the 
short pedicels are all closely bound together in bunches at the 
base. Paraphyses are naturally not so common in teleuto-sori 
as with uredospores, since the former do not need such protection, 
but they are found in P. Sonchi, P. dispersa, P. persistens, etc., 
although in these cases the so-called paraphyses are not at all 
of the same character as those found in uredo-sori, e.g. of Puc- 
cinia Baryi and others. When the teleutospore of a normally 
two-celled species becomes one-celled (by the omission of the 
last cell-division), it is called a mesospore: the mesospores of 
Puccinia are practically identical with the teleutospores of 
Uromyces and germinate like them. 
BASIDIOSPORES. 
All normal teleutospores develop under natural conditions 
in the same way; the cell-contents divide themselves into four 
parts, by a heterotype followed immediately by a homotype 
mitosis. 
This formation of what are really (and might with ad- 
vantage be called) tetraspores can take place in two ways :—the 
“basidium” can arise within the teleutospore-cell or outside it. 
The first method is the more primitive, the second is an 
adaptation to the tough cutinised or chitinous exospore of the 
more advanced types. In the Coleosporiacez the teleutospore, 
ie. the tetraspore-mother-cell, divides into four superposed cells 
(like the tetraspores of Corallina) while still in the sorus, during 
the autumn; each cell (spore) germinates, in late autumn, by 
protruding a sterigma through the thin gelatinous wall of the 
teleutospore and forming a basidiospore (conidium) at its apex. 
Zaghouania shows an intermediate form of germination. But 
in all the other families the cell-contents of the teleutospore, 
clothed only in a thin endospore, pass out through a germ-pore 
in the form of a longer or shorter tube (“basidium”); the 
contents pass to the distal end of this, and are there divided 
into four oblong cells. The median septum is sometimes formed 
first, and the two lateral ones after. In water the “basidium ” 
is usually long, in air it is short. In the absence of sufficient 
