APPENDIX 
METHODS 
For measuring conidia.—The following procedure was found con- 
venient. An ordinary bacteriological iridium wire was plunged into 
vaseline and then so laid across a microscope slide as to leave on it two 
complete, narrow, thin streaks of vaseline about 6 mm. apart. A small 
drop of water was then placed between these two vaseline lines and the 
conidia-sample added and evenly distributed. When the cover-glass 
was placed the vaseline prevented the conidia from scattering, and ren- 
dered it possible by means of the mechanical stage to measure every conid- 
ium, thus securing a more representative sample than would be the 
case if some conidia, perhaps of some particular class, were allowed to 
float away. 
In sampling from standard cultures for purpose of conidia-measure- 
ment, a portion of a shoot about 6 mm. long that was evenly and densely 
covered with conidia was removed to the slide. Shoots were all evenly 
and abundantly sporiferous except in cases where entire shoots or parts 
of shoots were paler and bore more aerial mycelium. 
To avoid unconscious selection in measuring conidia a mechanical stage 
was used, and all conidia encountered in certain predetermined posi- 
tions in the field of vision were measured. Length was measured 
from extreme tip to extreme base; breadth, at the thickest point. Meas- 
urements falling exactly between two classes were temporarily so recorded, 
and later distributed equally between the two adjacent classes. 
Measurements for coefficients are easily made by projecting the 
outline of the conidium, by means of a camera, upon quarter-section 
paper of convenient ruling. The paper may readily be oriented with 
the conidium in any desired relation. 
The rag doll for inoculations.—An adaptation of the rag-doll seed-tests 
was found useful in inoculations. The doll was made of a strip of 
cloth, 6X50 cm. which was rolled to a cylinder about 62.5 cm. and 
placed in a test-tube 2.525 cm. with water, and autoclaved. In use 
the roll was removed to a sterile Petri-dish 17 cm. in diameter, the water 
removed to the desired degree by wringing, and the doll unrolled by the 
use of sterile forceps (Pl. XXXIII). Seedlings raised aseptically were 
