170 



17. Many strains of Helminthosporium, some very different morpho- 

 logically from others, can produce some or all of the phenomena of infec- 

 tion (p. 136). 



18. Alternaria produces some of the marks of infection, including the 

 changes in the host-cell, the "callus," and entrance info the- host-cell. 

 Penicillium can not do this (p. 137). 



19. Wheat, corn, barley, rye, sorghum, Sudan-grass, and millet are 

 more or less susceptible to rot by Helminthosporium. 



20. Saltation, possibly mutation, is common in certain races of 

 Helminthosporium (p. 139). 



21 . Saltation is evidenced in general colony-character ; rate of growth ; 

 conidial production; conidial clusters; conidial length, breadth, septation, 

 and shape; mycelial characters, color, zonation, and sclerotial formation 

 (pp. 141-144). 



22. Certain saltants differed so markedly from their parent as to 

 far exceed the usually accepted specific limits (p. 141). 



23. Certain correlations and tendencies of characters in saltation 

 were noted (pp. 144-145). 



24. The saltants were, in the main, permanent in character (p. 145). 



25. They were permanent through the conidia (p. 146). 



26. What appeared to be reversions sometimes occurred (p. 147). 



27. Efforts to produce saltation artificially failed (pp. 147-148). 



28. The saltation was not due to mixed plantings, and can not be 

 induced by implanting or wounding (pp. 147, 148). 



29. Saltations are not due to parasites (p. 148). 



30. Saltations in abundance were derived from single-conidium 

 cultures (p. 149). 



31. Saltation is very frequent as compared with bud-variation 

 noted on potatoes and tobacco (pp. 150-151). 



32. Numerous variations in test-tube cultures are reported as prob- 

 able examples of saltations (p. 152). 



33. The Helminthosporium that causes wheat foot-rot belongs to 

 the H. sativum group, which consists of a large number of elementary 

 species (p. 167). 



