EUHOTIUM ASPERGILLUS. 



121 



fructification is met with. Fruit-bearing hyphae, not 

 branching and 0'3 10 mm. in length, arise from a 

 colourless mycelium consisting of delicate hyphae. 

 These fruit hyphas are globular at their upper end, or 

 dilated in the form of club-shaped bladders, on 

 which thin projections or sterigmata are arranged 

 radially. It is only in the eurotium forms that the 

 sterigmata are separated by septa from the bladders of 

 the fruit-bearers. The sterigmata give off at their 

 apices a succession of conidia, consisting of round or 

 somewhat oval cells 1 6 //. in diameter. Some asper- 

 gilli (A. clavatus, flavus, fumigatus) have unbranched 

 sterigmata; in the other three on the contrary they 

 are branched. The latter forms are also described as 

 stcrigmatocystis. 



Asp. flavus or flavcscens. Yellow or greenish 

 brown masses of fungi. 

 Conidia yellow or brown 

 Avith a fine warty surface ; 

 5 7 fju in diameter. 

 Sclerotia very small, 

 black. Grows best at 

 about +28 0. 



Asp. famigatus. 

 Greenish, often bluish- 

 grey masses very like 

 penicilliurn . Short conidia 

 bearers, curved forwards 

 to form a hemispherical 

 bladder, 8 20 //, in 

 diameter. Closely packed 

 awl-shaped sterigmata on 

 the hemispherical cup. Conidia round, smooth, with 

 single contour, for the most part colourless, 2'5 3 //, 

 in diameter. Sclerotia unknown. Thrives best at 37 

 40 C. 



Asp. nif/er. Dark brown masses. The knob of the 

 fruit hypha completely spherical. Sterigmata 20 100 

 l*> in length, branched like a hand. Conidia round, 

 when ripe blackish-brown ; diameter 3 '5 5 /u, Sclerotia 



Fig. 10. Aapergillus flavus X 300. 

 (After Siebenmann.) 



