354 



BOTANY 



a number of sterigmata arranged radially on the spherical, swollen ends of the 

 conidiophores (Fig. 275, D). The conidiophores are closely crowded together, 

 and constitute the white mould, afterwards turning to a blue-green. The Fungus 

 is frequently found on damp vegetables, fruit, bread, etc. 



JFiG. 277.— -Tuber nifiim. 1, A fructification in vertical section (X 5); a, the cortex; d, air- 

 passages ; c, dark veins of compact hyphce ; h, ascogenous tissue : 2, a portion of the 

 hymenium. (After Tulasne, from v. Tavel, x 460.) 



Penicillium crustaceum also forms a very common blue-green mould, particu- 

 larly on bread. The erect conidiophores constituting the mould are, in this case, 

 verticillately branched and bear at the extremities of each branch flask-shaped 

 ■cells, from which the chains of conidia are abstricted (Fig. 276). 



Spherical perithecia of Eurotium and Penicillium are produced later on the 

 mycelium, but in the case of the latter genus they are only rarely found. They 



