294 EUROTIUM. 



" suspensor ") to form a gamete more strictly, a game- 

 tangium or coenogamete, since here, as in other Muco- 

 raceae, the " gamete " is multinucleate. The double wall 

 between the " gametes " is absorbed, and a zygote is 

 formed the male and female nuclei fuse in pairs. 



The wall of the zygote, or fused gametangia, becomes 

 thickened, and the contents of the zygote become rounded 

 off and acquire a thick wall to form the zygospore, the 

 contents of which become dense and oily. 



The ripe zygospore wall shows (1) the original thin wall 

 of the fused gametangia, (2) the dark-coloured warty 

 epispore, (3) the thicker and more transparent endospore. 

 After zygospores have been formed, numerous cross-walls 

 appear in the hyphae of the mycelium. Sometimes the 

 twofgametes do not come into contact, but each gamete 

 may still develop into a zygospore-like structure an 

 " azygospore." 



Keep zygospores under observation in water in autumn, 

 and note that on germination the epispore bursts open, 

 and the contents, covered by the endospore, grow out to 

 form hyphae which build up a mycelium ; if this is culti- 

 vated, gonidiophores may be seen to develop, completing 

 the life cycle of the plant. 



EUROTIUM. 



425. Material for Study. Eurotium or Aspergillus herbario- 

 rum or Aspergillus glaucus (names given by different botanists to 

 the same plant) is the "green mould" which grows so commonly 

 on bread, preserves, fruit, cheese, etc. It often occurs along with, 

 or is replaced by, the still commoner " blue mould " (Penicillium). 



In damp bread kept under a bell-glass for a few days the 

 usual succession of moulds is (1) Mucor with its long black-tipped 

 gonidiophores ; (2) the bluish Penicillium with short gonidiophores 

 like miniature paint-brushes ; (3) Eurotium, rather like Penicillium 

 but with taller gonidiophores bearing a globular cluster of chains of 

 gonidia. 



426. Mycelium and Gonidiophores (Fig. 62). 

 Examine a piece of bread, or some apricot jam, bearing 

 gonidiophores of Eurotium ; shake some of these gently 



