298 MORPHOLOGY OF THE ASPERGILLACE^E. 



(B) Conidiophores without any (regular) distension at apex : 



1. Chains of conidia springing from sterigmata at the 

 apex : 



(a) Conidiophores with branches arranged in 



regular whorls ; conidia barrel-shaped . . Amblyosporium. 



(b) Conidiophores without regular whorls, simple 



or branched. Conidia globular or ellipsoidal : 

 (a) Conidia without mucinous matrix : 



1. Conidiophores unbranched, with a 



terminal tuft of sterigmata, and 



with or without terminal swelling . Citromyces. 



2. Conidiophores always more or less 



regularly branched, without termi- 

 nal swelling Penlcillium. 



(]8) Conidia united to a terminal head by 



mucinous matrix Oliocladium. 



2. Chains of conidia, without sterigmata, formed at the 



apex of the conidiophore ...... Briarea. 



The number of genera coming under consideration for our 

 purpose is limited to four : Aspergillus, Penidllium, Citromyces, 

 and Allescheria ( = Eurotiopsis), the sole distinguishing charac- 

 teristic of which consists in the shape of the Conidiophores, and not 

 in that of the asci. Indeed, this is still unknown in most of the 

 species now in question. Nevertheless, there does not appear to 

 be sufficient justification for excluding these latter species and 

 treating them separately as "fungi imperfect!," any more than 

 there is for separating the Mucorinece which produce zygospores 

 from those in which zygospores have not yet been observed. (In 

 this family also the spore-carriers in many cases form the sole 

 generic characteristic). Consequently, for the time being, we 

 will define these three main genera solely in accordance with the 

 form of the Conidiophores, and without reference to the presence 

 or special character of the asci (which would lead to a rearrange- 

 ment of the grouping), the latter being postponed until more 

 complete knowledge has been gained of the numerous species still 

 outstanding. At present the forms with Conidiophores of the 

 Aspergillus and Penidllium type may be divided into four groups, 

 namely, species with 



(a) Soft-skinned carpoasci with continuous development (perithecia) : 

 Aspergillus glaucus, A. fumigatus, Penidllium luteum. 



(b} Tough carpoasci with intermittent development (sclerotia) : Penl- 

 cillium glaucum, Aspergillus nidulans. 



(c) Sterile sclerotia, no asci being formed : Aspergillus flavus, A. ochra- 

 ceus, A. niger, Penidllium italicum. 



(d) Without any organs of the kind : Aspergillus oryzce, Penidllium 

 olivaceum, &c. The majority belong to this class. 



Groups (c) and (d) are only provisional at present, and inter- 

 mediate forms between the first two are also known to exist (A . 

 nidulans approximates to group (a)) ; moreover, there is no con- 

 cordance between the structure and development of the perithecia 



