52 PARKIN : FUNGI PAB LSFFIO 



which at firs! completely envelopes the conidial head and 

 then partially breaks away, that distinguishes at a glance 



ftficrocera from the conidial stage (Fusarium) of the scale 

 \ • ri;»> already described. The sporodochium of these 

 Latter lias been shown to be surrounded by a sheath of 

 sterile fibres, which, however, cling persistently to the mass of 

 parallel conidiophores within, and cannot be readily 

 detached as a separate covering. Such a sheath is only 

 evident mi microscopical examination, whereas that of Mi- 

 crocera is clearly visible to the unaided eye. Provisionally 

 1 should be inclined to keep the two genera apart on account 

 of this difference in the external covering of the sporo- 

 dochium ; Microcera, for example, to be characterized by 

 having its sporodochium surrounded by a loose separate 

 conspicuous sheath, and Fusariuin by possessing a closely 

 adherent inconspicuous one. 



Brown sterile Fungus associated with Aschersonia. 



Webber in his account of Aschersonia aleyrodis refers 

 to another kind of fungus growth* on the mealy wing 

 (. i U "/ ■' '/' S citri). Since it never has been seen to produce 

 any kind of f ruei ilieat ion. he names it for convenience in 

 Ins paper the "brown mealy wing fungus." He says it 

 attaelcs the insect in any stage of development, and is more 

 effeotive in destroying it than the Aschersonia ; to tjuote a 

 vinence, "In the grove where the fungus was lirst dis- 

 covered, its spread was so rapid during the past summer that 

 the mealy wing was almost eradicated.'' It Forms hard 



sun'., tli Hit circular brown pustules, 0\ r >-L' nun. in diameter, 



over the insects. Prom such stromata a Bilvery white 



mycelium Bpreadfl in all directions over the leaf surface, even 



13 mm. By this means other scales on the same leaf 



are readily Infected. 



Pustule- resembling these have been found on three 



ion on specie! of A leurodes. 



• W( bh r. lac, rii. pp.87 BO. 



