84 



MANUAL OF BOTANY 



apothecium. Hyphse from the sterile tissue are interwoven 

 with the filaments from the carpogonium, so that the apothecium 

 is derived from both. The surface layer of the apothecium is 



Fig. 838 



Fig. 840. 



Fig. 841. 



Fig.SiB. Development of the cleistothecium of EuroHum. a. Pollinoaium. 

 6. Carpogonium. c. The carpogonium beginning to form asoi. After 



Kny. Fig. 839. Mature cleistothecium of Burotium. e. Wall. d. Asci 



containing ascospores. After Kny. Fig. 840. Hymenial layer of the 



mycelium or hyphie of Peziza convexula. a, &, c, d, e, f. Successive stages 

 of development of the asci and ascospores intermixed with slender para- 



physes. After Sachs. Fig. 841. Perithecium of Peziza (natural size), 



with section showing hymenial layer (slightly magnified). After Kny. 



known as the hymenial layer {figs. 840 and 841). It consists of 

 a number of asci derived from the carpogonium, and of sterile 

 filaments springing from the vegetative hyphse. These are 



