Uredospores. 31 
trifoli, etc., the brown colour being due to the spore-wall. 
The colouring matter of the uredo and zcidiospores has 
been spectroscopically investigated by Bachmann.* He 
examined the ecidiospores of Gymnosporangium junipert- 
num and Puccinia coronata, and the uredospores of Me- 
lampsora farinosa, Triphragmium ulmarie, and Uromyces 
alchemille. Combined as it is with some oleaginous 
material in granules, and enclosed within the cell walls 
of the spores, it is exceedingly difficult to extract it with 
ether. But by adopting the saponification process of 
Kiihne tf and Hansen { he was able to arrive at the follow- 
ing conclusions. The above-named fungi give very similar 
spectra, namely two narrow absorption bands, one between 
6 and F, the other between F and G, showing that the 
pigment is the same in all cases; that it is very similar to, 
if not identical with, the colouring matter of most of the. 
yellow phanerogamous blossoms (the anthoxanthin of 
Hansen) although combined differently, and allied to the 
xanthophyll group. It is soluble in alcohol, ether, chloro- 
form, bisulphide of carbon, and benzol, and is coloured 
green by potassium iodide. 
As soon as the uredospore has arrived at its maturity 
it becomes separated below from the hypha which produced 
it (basidium, sterigma). This separation takes place by 
the basidia breaking off either close to the spore (Uredo) 
or at a short distance below, in which case the upper part 
of the basidium remains attached to the spore (Trichobasis). 
This separation is facilitated, if not caused, by the spore 
being pushed off by the continued formation of other 
* E, Bachmann, ‘‘Spektroskopische Untersuchungen von Pilzfarbstoffen ” 
(1886), pp. 21-23, figs. 27-31. 
+ W. Kiihne, “Ueber. lichtbestandige Farben der Netzhaut” (‘‘ Unter- 
such, d. physiol. Inst. d. Univ. Heidelberg”), bd. i. hft. iv. p. 347. 
{ F. A. Hansen, ‘‘ Der Chlorophyll Farbstoff ” (‘‘ Arbeiten des botan Inst. 
zu Wiirzburg”’}, bd. iii, hft. i. p. 126. 
