REPORT OF THE SOCIETY 61 



under slightly different conditions at the time of inoculation that these would 

 come definitely under the beta strain. 



4. A significant fact is that the alpha strain was not isolated out of fourteen 

 cultures from Canadian material. It is known to be present, however, as 

 varieties used here, known to be resistant to the beta and susceptible to the alpha 

 have been reported as susceptible at the Experimental Stations where they 

 have been tested. 



5. Culture 23 gave the widest range of those worked with but not wide 

 enough to take it out of the beta strain. It also differs widely from Form VIII 

 when using Leach's key. In testing 23 on carbon sources it is found to differ 

 from 2, a typical culture of the class to which the Canadian isolations are con- 

 sidered to belong, on maltose and asparagin. 



'o. The only variety found resistant to all the cultures used was Well's 

 Red Kidney. The varieties that proved resistant to the cultures from Canadian 

 sources were Navy, Minn. 73, Davis' White Wax, Yellow Six Weeks, Robust 

 and Fordkook Favorite (the latter not tested with culture 35). The last four 

 varieties are from Quebec and were susceptible to Leach's Form IV. 



7. Differences were noted on potato dextrose agar that remained constant 

 and made it possible to identify cultures 16, 35 and IV whenever grown on that 

 substratum. A study of these cultures in all the physiological experiments 

 show^ that they are constantly associated wherever tested. Cultures 16, 35 

 and IV were not similar, however, in infection capacities on the varieties of 

 beans inoculated. 



8. A comparison of the infection results of the cultures isolated during 

 the course of the work with their growth weights on mannitol shows that cul- 

 tures grouped from slight differences in infection also gav^e different average 

 weights. 



9. The triangulation experiment brings out the differences between cul- 

 tures 16 and 23 very markedly as the growth contours will partially fit into each 

 other like a lock and key. 



10. An attempt was made to secure the perfect stage from any of the isola- 

 tions by growing several cultures in one plate so that the colonies would run 

 together. No sign of a perfect stage was evident. 



Dept. of Botany, 



Macdonald College, 

 P. Q. Can. 



Bibliography. 



1 . Barrus, Mortimer F. Variation of varieties of beans in their suscep- 

 tibility to anthracnose. Phytopath. 1: 190-195. 1911. 



2 '. .Varietal susceptibihty of beans to strains of Colletotrichum 



hndemuthfanum (Sacc. & Magn.) B. &: C. Phytopath. 8:589-614. 

 1918. 



