COIIN, ON EMPUSA MUSC.«. 157 



the proboscis is protruded, and firmly adheres by suction to 

 the wall, &c. ; in consequence of their adhesion by this part, 

 and by the outstretched legs, the dead insects remain at- 

 tached to the surface, just as if they were still alive ; their 

 bodies dry completely, and become excessively friable. 



10. The blood-fluid, as well as the viscera, are gradually 

 consumed by the parasitic Empusa, whose radical extremity 

 continues to elongate, whilst the opposite end expands into a 

 clavate head. Owing to the development of the parasitic 

 growth, the abdomen of the insect continues to enlarge more 

 and more, and the rings of the abdomen to separate from 

 each other. 



11. Eight to ten hours after death the delicate membrane 

 by which the segments are united, is perforated by the clavate 

 extremities of the Empusa-ce\h,, which then appear on the 

 exterior, forming white zones, which continue to increase in 

 width, between the rings of the abdomen. 



12. The clavate exterior extremity of the fungus-cells 

 grows rapidly, and by the formation of a dissepiment at the 

 lower (internal part) becomes divided into two, so that the 

 fungus now consists of two cells — a radical and a peduncular. 



13. The peduncular cell is elongated at the apex into a 

 short, cylindrical process, which soon expands into a vesicular 

 form, is filled with the plasma Avhich continues to flow into 

 it, and separated from the lower portion by a transverse dis- 

 sepiment. In this way is formed the unicellular spore, which 

 soon assumes a bell-shaped form. The Empusa, conse- 

 quently, is a typical, tricellular plant. 



14.. From the elastic pressure exerted by the peduncular 

 cell, the spore is projected to the distance of about an inch. 

 The scattered spores form a white dusty area around the 

 dead flies, and adhere firmly to their wings and legs. 



15. The spores are often found enclosed in vesicles, and 

 thus become assembled into little masses ; the origin of these 

 vesicles has not yet been ascertained with certainty. 



16. Success has not yet attended attempts to efieet the 

 germination of the spores, either in water or moist air, or 

 by artificially affixing them upon or introducing them into 

 the interior of living flies. 



17. If a fly dead of this disease be placed in moist air, 

 fungi are developed upon it, but belonging to forms which, 

 manifestly, have no genetic connection whatever with Empusa 

 {PeniciUium) . 



18. At present, consequently, there is no evidence what- 

 ever to show the relation of the Empusa-ST^ores to the ap- 

 pearance of this fungus and of the disease, whilst the 



