AECIAL STAGE OF ALSIKE CLOVER RUST 
463 
TABLE I. 
Stage I Aeciospores 
Host 
Arthur 
o' 
'O 
as 
Sydow 
Howell 
Davis 
o 
a> 
a 
VI 
Size 
Temp. 
Temp. 
Size 
Stand 'rd 
l| No 
T. repens — 
15- 17 x 
16- 21 
14x23 
14-18 x 
17-21 
14x22 
15-18 
26°0 
3 
20 
.6-24 X 
16-30 
18-22 x 
22-26 
50 
T. pratense . 
T. hybridum 
— 
— 
27 
3 
12 
25-35 
4 
14 
Ll. 
'8-24 x 
20-29 
10-22 x 
15-26 
18-22 x 
22-24 
17-20 x 
21-24 
73 
54 
Fig. 92. — Peridial cells of Aecia from Alsike Clover rust. Camera lucida 
drawings from prepared slides of material collected out of doors May 13, 
1916. 1, A shows the inner surface of a peridial cell; C, The striated outer 
wall ; E, The large lumen of the cell. Note the overlapping of the outer 
walls, also the thickness compared with the inner wall. For measurements 
see table II. 2 and 3, Other peridial cells of the same rust. 
The proper names used as headings signify the authors whose 
reports are used. The germinating temperatures are given in 
degrees centigrade, beginning at the top, minimum, optimum 
and maximum in order. ‘ ‘ Number ’ ; in the last column refers 
to the number of spores measured. The measurements given 
30 
