258 BOTANICAL GAZETTE [October 



Fig. 20. — Development near end of hj^jha with branches budding from 



mass. 



Fig. 21. — Irregular meristogenous development. 



Fig. 22. — T3T)ical compound meristogenous development with 3 parallel 



hyphae involved. 



PLATE XV in 



Figs. 23, 24. — Phoma from clover: beginnings of pycnidia. 



Fig. 25. — Slightly older stage with a few short budding branches. 



Figs. 26, 27. — Later stages with one end enlarging slightly. 



Fig. 28. — Phoma from grape: mycelial threads with different stages of 

 pycnidial development. 



Fig. 29. — Beginning stage: simple meristogenous. 



Figs. 30-32. — Later stages. 



Fig. 33. — Mature pycnidium. 



Fig. 34. — P. cichorii Passr. : early stage in development ; short cells formed 

 which divide and branch. 



Fig. 35. — Early stage in which is much branching. 



Fig. 36. — Medium stage in simple meristogenous development. 



Fig. 37. — Typical compound meristogenous development. 



Macrophoma 



Fig. 38. — M. citrulli (B. and C.) Berl. and Vogl.: 2-celled stage in origin 

 of pycnidium, from drop culture; simple meristogenous development. 



Fig. 39. — Same 12 hours later. 



Figs. 40, 41. — Early stages of other pycnidia, from drop culture; slight 

 variation from simple meristogenous type in that many branches are involved. 



Figs. 42, 43. — Early stages in which much branching takes place; drop 

 culture. 



Figs. 44, 45. — Early stages from Petri dish culture. 



Figs. 46, 47. — Later stages. 



PLATE XIX 



Fig. 48. — M. citrulli (B. and C.) Berl. and Vogl.: symphogenous develop- 

 ment in which branches from a number of main strands interweave. 



Fig. 49. — Later stage in which a winding of the hyphae and ceU division 

 have taken place forming a pseudoparenchymatous mass. 



Sphaeronaema 

 Figs. 50-52. — S . fimbriatum (E. and H.) Sacc: early stages of pycnidium 

 in which a hypha coils, branches, and divides to form knotlike mass. 



Sphaeropsis 



Fig. 53. — S. malorum Pk.: Early stage in symphogenous development in 

 which branches a, b, c interweave near their ends to form a ball. 



Fig. 54. — Interwoven hyphae in early stage of symphogenous develop- 

 ment. 



