Christman—Wintering of Grain Busts. 
101 
Temperature records at Stockholm. 
Years. 
Nov. 
Dec. 
Jan. 
Feb. 
Mar. 
Max. 
Min. 
Max. 
Min. 
Max. 
Min. 
Max. 
: Min. 
! 
Max. 
Min. 
1890-1891. . 
52 
2 
41 
2 
41 
— 9 
52 
2 
48 
0 
1891-1892. 
50 
16 
46 
4 
41 
— 4 
46 
—18 
52 
4 
1892-1893. 
48 
12 
45 
— 4 
34 
—16 
35 
-25 
53 
-14 
1893-1894. J 
1 48 
12 
45 
16 
In a recent paper 1 Klebahn describes observations which pos¬ 
sibly suggest the existence of a my coplasm such as Eriksson and 
Tischler 2 have described in their latest communication on the 
subject. Klebahn figures and describes minute granules within 
the host cells which stain, as he says, like the nuclei of the rust 
hyphae. These granules are very small and do not show the 
membrane, chromatin, and nucleole, which I have always found 
in the nuclei of rusts whether collected in winter or summer. 
Klebahn himself is doubtful whether the structures observed 
are not artefacts. 
In the winter of 1 892-1898, Hitchcock and Carleton 3 made 
a series of observations on the wintering of P. rubigo-vera D. C. 
at Manhattan, Kansas. They record the germination of uredos- 
pores collected November 5th, January 9th, January 17th, Janu¬ 
ary 24th, January 25th, February 25th, and March 1st. They 
also record the maximum and minimum temperatures of each 
of the winter months. 
Maximum. Minimum 1 . 
December . 67° —9° 
January . 53° —1° 
February . 61° —6° 
Considerable snow covered the ground during the winter. 
Carleton 4 gives it as his opinion that in the latitude of Man- 
1 Klebahn,—Einige Bemerkungen uber das mycel des Gelbrostes. 
Bericbte der Bot. Gesell., XXII, 1904. 
2Loc. cit. 
3 Hitchcock and Carleton,—Preliminary report on the rusts of grains, 
Kan. Agr. Exp. Station, Bull. 38, 1893. 
^ Hitchcock and Carleton,—Rusts of Grains, Kan. Agr. Exp. Station, 
Bull. 46, 1894. 
