THE ENTOMOLOGIST. 035 



dying in this jjosition ? — Mr. Woodhouse describes very 

 minutely the appearance of flies found in this condition. I 

 offer the following ex})lanation, which is in part problematical, 

 and is almost entirely derived from the publications of others. 

 The disease is attributed to a cryptogamic plant, but whether 

 a fungus or a member of the comprehensive and somewhat 

 heterogeneous order of Algae, we have no positive decision ; 

 botanists seem divided in opinion on the point. Amongst 

 those who have written on this plant are Pringsheira, Archer, 

 De Bary, Unger, Thuret, Tute, Griffith and Henfrey, Braun, 

 Robin, Cienkouski and Nageli. The prevailing opinion 

 seems to be that it is an imperfect terrestrial form of 

 Saprolegnia ferax, a fungus of which I know nothing except 

 the name. This particular form is called Sporendonema 

 Muscat, and has its habitat in the bodies of flies. Empusa 

 aulica is another fungoid growth of a like nature. These 

 fungi — I call them so, not for the purpose of expressing an 

 opinion on their true character, but simply for convenience — 

 these fungi, or rather their spores, are found to exist in multi- 

 tudes in the bodies both of diseased and of apparently healthy 

 flies: the spores are found floating in the blood of the flies; 

 but in a short time they seem to exhaust all the fluid matter, 

 and then expanding, or rather lengthening into filaments, 

 called mycelia, they at last completely fill the body of the fly 

 with a substance resembling cotton-wool, and the fly at last 

 succumbs to starvation, although to all appearance replete 

 with food, when the fungus makes its appearance at the 

 interstices of the segments and at the spiracle, and throws 

 out spores all round, forming a kind of circle round the fly, 

 entirely composed of these spores and the filaments which 

 emanate therefrom. There seems to be something glutinous, 

 or to say the least, adhesive, in this fungus, for through its 

 instrumentality the fly becomes so firmly attached to the 

 pane that it is frequently impossible to remove it without the 

 loss of a leg. With regard to the fly being fixed to the 

 window-pane, I can only suggest that this circumstance 

 exhibits no selection on the part of the fly, but simply arises 

 from the circumstance that in this selection they are pecu- 

 liarly exposed to observation. — Edtvard Newman. 



James Deane. — Miisca jjluvialis. — •! enclose a small 

 sample of a species of fly, by which I was much troubled for 



