BASIDIOSPORES - 
, moreover, the four cells may not be formed ; the “ basidium ” 
wy resemble, more or less, an ordinary germ-tube and possibly 
iy function as such. Even if the four cells are formed, they 
ay germinate by the protrusion of a germ-tube, which pre- 
mably can cause infection by penetrating the cuticle (see 
vons, 1912, p. 225). But, with access of air, each cell forms a 
srigma and a basidiospore as previously described. These 
nidia are obviously adapted for wind-dispersion. If they 
ght on a suitable surface, they send forth a short tube which 
variably bores straight through the cuticle into the under- 
ing epidermal cell of the plant, and there begins to form 
mycelium. The only instance in Puccinia known to the con- 
ary?, out of the many observations that have been made and 
rured of this process, is De Bary’s record of the case (Ann. 
wi. Nat. Bot. 4. xx, 1863, pp. 88-9) where the germ-tubes of the 
basidiospores of Puccinia Dianthi 
(q.v.) penetrated through the stom- 
atal openings of Dianthus barbatus 
(Fig. 24). In grasses and sedges, it 
is easy to see that the siliceous 
we cuticle would present a great ob- 
Pads oe peat ia stacle to the entry of such a tube, 
ee Play trian while not impeding germ-tubes 
ing straight for the stomata which enter through a stoma, and 
(after De Bary’s figure). 390. this is probably the reason why 
cidia are so rare on the order Glumiflore. In the hetercecious 
yecies no one has yet brought forward ipdisputable evidence 
» show that basidiospores can infect the host which bore the 
‘leutospores, although statements to that effect are made. 
The shapes of basidiospores are not irregular; they are 
iore or less constant in each group. In Puccinia and Uromyces 
1ey are ovate, somewhat flattened on one side, or kidney- 
raped. In the Phragmidiee they are almost spherical; in 
1e Melampsoracee small and roundish. In Endophyllum they ° 
re ovate; in Coleosporium they are large and ovate and a 
1 Statements have been made of other instances, but most of them on 
sufficient authority, and some have been specifically disproved. The genus 
oleosporium seems, however, to be an exception. 
