282 



COMPARATIVE MORPHOLOGY OF FUNGI 



The origin of Diaporihe from Onomonia is very evident. In the sim- 

 pler species the transition is very gradual. The compound fructifications 

 have arisen from the clustering of perithecia and the development of a 

 light-colored, differentiated entostroma circumscribed by a dark marginal 

 zone. The imperfect forms consist of a Phomopsis type of fructification 

 with an enclosed locule formed in an ectostroma which is intimately 

 associated with the entostroma beneath, when that tissue is well developed. 



In Diaporihe leiphaemia, which occurs on damp fallen oak twigs (Fig. 

 185, 1) between periderm and bark parenchyma, the hyphae intertwine 

 to a narrow plectenchymatic covering, the fundament of the ectostroma ; 

 this develops outwards to a verucose head and thereby accomplishes the 



'§1(23 gzz> CB§<p2ia <33><ffi> • <bz'.<sp»«>— — ]^ j^ 



Fig. 185. — Diaporthe leiphaemia. 1. Section of old pycnium. Diaporihe syngenesia. 

 2. Section of old pycnium. Pi, original pycnium with large conidia; Pi, secondary pseudo- 

 pycnium with smaller conidia. Melanconis stilbostoma. 3. Section of young ectostroma, 

 bearing conidia. 4. Diagrammatic section of mature fructification. Kon, shows the 

 remnants of conidial layer between periderm and stromatal surface. Ect, ectostroma; 

 Ent, entostroma; Per, periderm; Rp, bark parenchyma. (After Ruhland, 1900.) 



opening of the periderm. Hereupon it is differentiated within to a large 

 pycnium whose interior is entirely covered with conidiophores cutting 

 off hyaline bacillif orm conidia. Subsequently at the middle of the base of 

 the pycnium, conidial formation stops and the ectostroma which lies 

 there develops to a comparatively high plectenchymatic cylinder which 

 projects into the cavity of the pycnium and divides lengthwise into two 

 special sinuses. Diaporthe oxyspora (Wehmeyer, 1928) agrees with this 

 type of development, having a Phomopsis conidial stage. 



In Diaporthe syngenesia (D. Berlesiana), the conidial hymenium is 

 more elaborate. The ectostromatal layer, which separates pycnium 

 from periderm, is much more developed than in D. leiphaemia. After 

 the periderm is ruptured, conidial formation overlaps to the face of the 

 distal ectostromatic layer (Fig. 185, 2) and thereby forms on the outer 



