30 NATURAL CONTEOL OF WHITE PLIES IN ELOKIDA. 



threads interlace to form a dense paper}'' membrane covering the 

 lower surface of the leaf, and mycelial threads growing down the 

 petioles and along the branch to the next leaf are often so numer- 

 ous as to form a like coating on these. The authors have on many 

 occasions seen watershoots 5 feet long with the undersides and 

 petioles of the leaves, and the stems of the shoot, wholly coated with 

 this dense mycelial growth. In one instance there were brownish 

 sporelike bodies, above mentioned, scattered over the entire mycelium 

 on the stem of the watershoot and along the edges and upper surface 

 of the leaves. (See PL VII.) 



DEVELOPMENT. 



The development of the brown fungus on the larvje and pupse 

 does not difl'cr materially from that of the red and yellow Ascher- 

 sonias already described, with the exception that after the hyphsG 

 have fdled the insect body and have broken out around the edges, 

 the stroma which then forms does not produce fruitmg bodies but 

 from them there grow out slender mycelial filaments which extend 

 tihijiigreater distance than those of the Aschersonias and partly take 

 the place of the spores of the latter in hifectmg other larvae and 

 pupa?. As with the other fungi, insects may be Idlled without the 

 formation of tlie characteristic complete stroma, or the stroma may 

 be restricted in its growth to the margin of the insect. Often when 

 several insects close together are infected, one large irregular stroma 

 will develop over them all. 



The junior author has followed from day to day the growth of the 

 mycelium of the brown fungus toward dead pupa?, and the subse- 

 quent development thereon of the characteristic stromas. This 

 fungus is therefore definitely known to be partially saprophytic. 

 This was previously suspected, since on leaves mfected by it nearly 

 all specimens within reach of the mycelium are overgrown and the 

 Usually large percentage of specimens dead from unknown causes is 

 not apparent. The stroma frequently does not develop normally 

 except around the margin, leaving the greater part of the body of 

 the insect and the segmentation easily distinguishable. This con- 

 dition is probably due in some cases to the effect of dry weather on 

 the growth of the fungus, but it is considered by the authors to be 

 due more often to the development of the fungus on the body of a 

 dead msect. 



DISSEMINATION. 



Although Dr. Webber was unable to discover any fruiting bodies 

 of the bro^vn fungus, his observations led him to believe that the 

 mycelial filaments, spreadmg out over the surface of the leaf from 

 larvae already infected, have the power to infect other larvae and 

 pupae with which they come into contact, and that it seemed probable 



