400 Dastur . — Cytology of Tilletia Tritici , ( Bjerk .) Wint. 
methods give equally good results. The spores were treated with the fixing 
solution for thirty minutes or more. The preparations were bleached with 
hydrogen peroxide and stained with Heidenhain’s haematoxylin. Breinl 
stain and the combination of gentian-violet and orange G were also used 
to check the results obtained with haematoxylin. 
The spore germinates by rupturing its wall and produces, as a rule, 
one promycelium. At times two or three germ-tubes or promycelia are 
put forth, but all except one degenerate. As in T. caries } the nucleus of 
the spore passes undivided into the promycelium. The migration of the 
nucleus into the promycelium does not necessarily take place immediately 
after the promycelium is developed ; at times it is long delayed, so that 
there may be a long promycelium without a nucleus. As observed by 
Dangeard, the first division of the nucleus may take place soon after it 
enters the promycelium (PI. XX, Fig. 2), or the division may be delayed for 
a time (PI. XX, Fig. 4), and may be even subsequent to sporidia formation 
(PI. XX, Fig. 1). Rawitscher 2 states that the first division, which, he thinks 
may perhaps be the reduction division, takes place in the spore ; it is 
evident that he merely assumes this, because he has been not only unable 
to see the first division on account of the opaque wall of the spore, but he 
has not even observed the later divisions as a result of which eight nuclei 
are found in the promycelium. He says : ‘ Die ersten Teilungen desselben— 
wahrscheinlich die Reduktionsteilungen — liessen sich indes bisher noch nicht 
beobachten, da sie in den untersuchten Fallen bereits in der undurchsichtigen 
Spore vor sich gingen. Sobald aber deren ganzer Inhalt in den Keim- 
schlauch eingewandert ist, lassen sich darin zunachst stets acht Kerne zahlen.’ 
Paravicini 3 also states that the nucleus of the spore divides at the time of 
germination and that one of the two nuclei passes into the promycelium. 
The same author has further shown that with the division of this daughter 
nucleus the tip of the promycelium becomes bifurcated and a nucleus enters 
each of these branches. The nuclei again divide twice successively and thus 
eight nuclei are formed ; at the same time eight small projections are 
developed at the tip of the promycelium, and each of these small projections 
bears what he calls an ‘ endconidium ’, each of which is provided with one 
nucleus. Neither Dangeard, Rawitscher, nor the writer has observed the 
division of the nucleus to be associated with the threefold bifurcation of 
the tip of the promycelium and the presence of the nuclei in the very young 
sporidia. The divisions of the original nucleus do not take place at any 
particular stage in the development of the promycelium. As in the case of 
the first division the ultimate divisions may be delayed till the formation 
of the sporidia. Thus there may be eight nuclei in a promycelium which 
shows as yet no trace of sporidial formation (PI. XX, Fig. 5) ; and there may 
1 Dangeard, P. A. : loc. cit., p. 265. 2 Rawitscher, F. : loc. cit., p. 312. 
3 Paravicini, E. : loc. cit., p. 76. 
