120 



of cylindricity. For these determinations only conidia of approximately 

 modal length were used, and to obviate unconscious selection, measure- 

 ments were made of only the left side of the conidium, the basal end being 

 toward the observer. Determination from 11 conidia of H. No. 1 of sub- 

 cylindrical shape gave a coefficient of .74, while that frorrPST elliptical 

 conidia was .67. 



The above findings for H. No.*l are as follows: 



Coefficient of longitudinal eccentricity 



All conidia 43 



Elliptical conidia 42 



Subcylindrical conidia 45 



Coefficient of cylindricity 



All conidia 70 



Elliptical conidia 67 



Subcylindrical conidia 74 



Determinations of the coefficient of cylindricity made from drawings 

 of Dr. Ravn (91) gave for H. gramineum and H. avenae respectively .86 and 

 .95, showing a much higher coefficient than is given by any of the forms in 

 my collection. 



A convenient method of measuring conidia for coefficients is given on 

 page 179 of the appendix. 



Conidial length. From five separate plates, a, b, c, d, and e, inoculated 

 with H. No. 1 under standard conditions, Graphs 36-40 (Fig. K) of conidial 

 length were made. Two additional graphs were made from plate e, one 

 of which is designated as e 1 '. The data pertaining to these graphs are 

 given with the others (Fig. K). 



The differences between the means of conidial length on plates a to e 

 and e' are as follows: 



Plates Differences between means Plates Differences between means 



a-b +0.70 .21 



a-c +0.62 .24 



a-d -0.78 .23 



a-e +2.03 .24 



a-e' +0.50 .16 



b-c -0.07 .22 



b-d +0.08 .23 



b-e' -0.19 .16 



c-d +0.16 .23 



c-e + 1.40 == .24 



c-e' +0.11 .17 



d-e +1.24 .25 



d-e' -0.28 .18 



e-e' -1.52 .19 



b-e +1.32 .24 



Since the various plantings on these plates were all from the same in- 

 oculum, made at the same time, and under as nearly identical conditions 

 as possible, and so kept, the rather large difference in means seen, particu- 



