326 MORPHOLOGY OF THE ASPERGILLACE^. 



sterigmata of the insignificant, club-shaped globule (15-20 // 

 thick), which recalls A. fumigatus, are usually confined to the 

 upper half, and generally produce globular, smooth (or finely 

 dotted), very small conidia (3 p. in diameter) in long chains adher- 

 ing in the form of tough masses. Septation and branching of the 

 stems (sometimes very irregularly) seem by no means infrequent. 

 According to Eidam's observations on the development of the 



FIG. 176. Aspergillus nidulans. 



Conidiophores with branched stcrig-inata (i and 2), conidia (4), ascospore with globular 

 capsule (5), prepared separately at 6, and shown in section at 7, with asci (8), 

 spores (9), one of them with germinating- tube. Magn. of i and 2, 330; of 3 

 120 ; oi 4, 1000 ; of 6, 85 ; of 7, 170 ; of 8, 400. (After Eiilam.) 



ascospore, this latter is formed from two hyphse (instead of one, as 

 in the case of A. glaucus], the one developing into the tough, 

 stratified, pseudoparenchymatous integument, whilst the other 

 furnishes the internal tissue forming the aisci. Several weeks 

 pass before the development is complete, and the ascospore, which 

 is then provided with tough, dark blackish red walls, is ripe. The 

 gradually evolved, ovoid ascus, 10-11 p. in length, encloses eight 

 smooth, lenticular spores (about 5 jj. by 4 p), provided with a 

 longitudinal furrow and a tough purple epispore, which bursts in 

 two during germination. Analogous to those of A. fumigatus and 

 A. Rehmii, the sclerotia (0.2-0.3 /x in diameter) are surrounded by 

 a shell of peculiar, yellowish hyphse, which are distended like 

 bubbles this feature is absent in A. ylaucus and A.pseudoclai-atus. 



