234 



COMPARATIVE MORPHOLOGY OF FUNGI 



Gemmae and conidia are known as imperfect forms. The gemmae 

 are mostly hyaline or brownish and occasionally verrucose; they develop 

 (especially in drying cultures) on hyphae, singly or catenulately, and 



Fig. 150. — Nectria cinnabarina. A. Conidial stromata (shown light) perithecial 

 stromata (dark) erumpent from bark of host, B. Section through a stroma which is still 

 cutting off conidia at the top while it has formed perithecia on the sides. C. Ascus. D. 

 Hypha with microconidia. Nectria ditissima. E. Perithecial layer breaking from the 

 bark. F. Longitudinal section of conidial fructification. Nectria sinopica. G. Ascus. 

 H. Part of pycnium. Nectria inaurata. J. Ascus without and with sprout cells. Nectria 

 oropensoides. K. Coremium. (A X 10; B X 20; C, D, G, J X 350; E X 3; F, H X 380- 

 K X 60 ; after Tidasne, Brefeld and Lindau.) 



show little individuality. The conidia, also in exhausted nutrient 



solutions, may thicken their walls and change into a sort of gemmae. 



The conidia are hyaline or yellowish, brownish, orange red, etc., 



and are cut off, either terminally or laterally, from hyphae which are 



