UPON SCALE-INSECTS. 47 



Association in 1900, as belonging to the Dematiaceae, probably 

 near the genus Campsotriehum. On closer examination it 

 agrees better with the neighbouring genus Peziotrichum 

 founded by Saccardo in 1893,* to receive a fungus collected 

 in Australia on twigs and thorns of Bursaria spinosa. It 

 differs in having spherical instead of cylindrical conidia,antl 

 so agrees with Botryotrichum in this respect. 



The Ceylon fungus appears to the naked eye as a minute 

 tuft of brown or black bristles standing up around the scale, 

 subtended by a small amount of brown mould covering and 

 surrounding the scale (figs. 56 and 57). A microscopic 

 examination reveals the following structures. From below 

 the scale proceed horizontal hyphae ramifying a little way 

 over the leaf surface. These produce at frequent intervals 

 very short side branches, each bearing a large apical spheri- 

 cal conidium (figs. 60 and 61). The upright sterile bristles 

 are attached to the rest of the fungus close to the margin of 

 the scale. In fact the external visible part of the fungus 

 consists : (1) of a creeping mat of septate hyphae covering 

 and surrounding the scale, and bearing on short lateral pro- 

 cesses single conidia ; and (2) of sterile stouter septate 

 hyphse cohering together to some extent in bundles and 

 standing erect around the periphery of the scale. The 

 whole fungus, with the exception of the hyaline tips of the 

 bristles, is brown throughout, including the conidia. The 

 spherical conidium, 16/i in diameter, has a yellow-brown 

 wall and contents which stain deeply with iodine, suggest- 

 ing the presence of glycogen. 



The main conidial hyphae have a thickness of 4-5^ , and 

 the bristle ones of 8-10/* near the base. These latter taper 

 somewhat towards the apex, are regularly septated and have 

 ;i colourless slightly swollen apical segment (figs. 58 and 59): 

 total length 0*8-1 mm. They cling together as a rule in 

 bundles of 12 or so, the lower parts are often separate, but 

 the upper parts are closely coherent. Special sterile hyphae 



* Saccardo, Hedwigia, 1893, p. 58, and Syll. Fung-. XI. 18%, p. 614. 



