BY D. McALPINE. 493 



sporidia as minute, oblong. Then Thuemen^' speaks of the 

 perithecia with net-like surface and oblong, very small, bright 

 brown, 2-3-septate spores escaping by a pretty large opening at 

 the apex. Next, Saccardof describes the perithecia as elongated, 

 often fusoid, ^ mm. high, and spermatia as 7 /^t long. As no asci 

 were found, it is doubtful if the bodies referred to were really 

 perithecia, but the 2-3-septate sporidia of Thuemen are very 

 different from the 5-6-septate sporidia of the present form. 



Cajjaoduim saliciuum, Mont., has been determined by Farlow 

 on orange leaves in America, and there is considerable resemblance 

 in many points, but the asci and sporidia show marked distinc- 

 tions. The asci measure 40-45 x 24 ;:i, while here they are on an 

 average 70-80 x 19-20 fj., or nearly double the length. Then the 

 sporidia correspond well in size in both cases, but instead of being 

 tri-septate here, they are 5-6-septate. 



Evidently, although the " sooty mould " is so common in Aus- 

 tralia wherever Citrus fruits are cultivated, it has not yet been 

 scientifically determined, and I propose naming it CapnoduDu 

 citricolum. 



PolymorpJdsm. — Polymorphism literally means many forms, 

 and has reference to the various forms assumed by fungi, especiall}' 

 in their reproductive bodies, in the course of their development. 

 But the change of form may be accompanied l)y a change of host, 

 and this is distinguished as hetercecism, or there may even be a 

 desertion of the host, and then it is termed lipoxeny. The change 

 of form referred to here occurs consecutively or simultaneously 

 on the same individual, and all the changes were found even on 

 a small portion of the same leaf. 



In the present instance there are two different kinds of hyphte 

 associated — the thin- walled, colourless or slightly coloured hyphse; 

 and the thick-walled, distinctly coloured hyphpe — and each has its 

 own reproductive bodies. 



* Die Pilze — Fungi pomicoli, p. 53 (1885). 

 t Syll. Fung. I. p. 78 (1882). 



