250 



STRUCTURAL BOTANY 



small flask-shaped receptacles called spermogonia (Fig. 



102), each of which, in our type and its near allies, is 



sunk in a wart-like elevation of 

 the thallus. The interior of the 

 spermogonium is occupied by a 

 net-work consisting of sterile cells 

 and fertile lasidia. From the 

 latter, excessively minute cells, 



FIG? 102. - lp/^ti~a~a- the spermatia, are budded off 

 veruienta. Longitudinal (Fig. 103). The nature of these 



section of a spermo- ./-IT i_ j- 



gonium, embedded in an spermatia has been much dis- 

 elevaiion of the cortex. pu ted i there appears to be 



Magnified. (After Darbi- r . , ., r ^ ,. 



shire.) weighty evidence tor regarding 



them, at least in certain cases, 

 as the male cells of the Lichen. 



FIG. 103. Physciapulvcrulcnta. Portion 

 of the tissue inside a spermogonium, 

 showing the groups of sterile cells (G), 

 and the basidia bearing spermatia. 

 Highly magnified. (After Darbishire.) 



In most species investigated the apothecium has been 

 found to arise from a special cellular filament, the carpo- 



