apig] KEMPTON—PYCNIDIUM 259 



Fig. 55. — Slightly later stage. 



Figs. 56, 57. — S. citricola McAlp.: very early stages in origin of simple 

 meristogenous development of pycnidia. 



Figs. 58, 59. — Slightly later stages. 



Figs. 60-63. — Later stages with short hyphae branching from masses. 



Figs. 64-66. — Unusual examples of developments in which more than one 

 hypha is involved; compound meristogenous. 



Coniothyrium 

 Figs. 67, 68. — C. pyriana (Sacc.) Shel. : early stages in development. 

 Figs. 69, 70. — Later stages in which numerous branches from dividing 

 mass are involved. 



Fig. 71. — Pseudoparenchymatous mass from which a pycnidium arises. 



PLATE XX 



Fig. 72. — Coniothyrium species from laboratory air: early stage showing 

 short cells and short branches as origin. 



Fig. 73. — Slightly later stage in which cells and branches from main hypha 

 divide into short cells and anastomose. 



Fig. 74. — Stage slightly more developed than fig. 73 ; slight variation from 

 simple meristogenous type. 



Septoria 



Fig. 75. — 5. polygonorum Desm.: beginning stage of simple meristogenous 

 development. 



Fig. 76. — Development in which original hypha and numerous branches 

 are involved. 



Fig. 77. — Pseudoparenchymatous primordial mass formed by symphoge- 

 nous method. 



Figs. 78, 79. — 5. scrophulariae Pk.: early stages in compound meristo- 

 genous development. 



Fig. 80. — S. helianthi E. and K. : early stage in beginning of simple 



meristogenous development. 



Fig. 81. Later stage. 



Sphaeronaemella 



Fig. 82. — 5. fragariae S. and P.: early stage of simple meristogenous 

 development. 



Fig. S^. — Later stage in which branches and original hypha have anasto- 

 mosed to form a mass on one side of main strand. 



Fig. 84. — ^Later stage in which mass surrounds main strand. 



Fig. 85. — ^Late stage which has developed by a winding and dividing of 

 hyphal branches from a few cells upon one side of main strand. 



Gloeosporiiim 

 Fig. 86. — G. rufomaculans (Berk.) Thiim.: early stage of meristogenous 

 development; this method rarely occurs. 



