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 6X2.5 cm. and 

 placed in a test-tube 2.5X25 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 (PI. XXXIII). Seedlings raised aseptically were 



