88 Bulletin de la Société Entomologiqiie cV Egypte 



of a cockchafer, the contractions of the newly moul- 

 ted PZuipusa must drive tosvanls the wings the blood 

 jiiass accumulated in the thorax. 



The supply of air enclosed wilhni llie crop must 

 also have some inlluence. The crop oi the Empusa, 

 relatively larger and filling by itself the anterior half ol'. 

 the abdomen, is seen on dissection to be much swollen 

 Acting as an elastic cushion this sack swollen with air 

 must, whenever the body walls contract, help to increase 

 the pressure of the liquid within the abdomen. 



Especially rapid pulsations ol the dorsal vessel 

 have been observed in grasshoppers al the time oi 

 moulting by Künckbl d'HeiiclLais (1884). It is highly 

 probable that the same phenomenon occurs inManlidae. 



The meso-and metathoracic pulsatile organs in all 

 probability also play an imjiortant part. 



These were discovered by Brochüh (lUKì) in D\- 

 tisciis ììKirgiatalis and consist of a mesotergal pulsatile 

 organ placed just binealh the scutellum and a mela- 

 tergal pulsatile organ under the metathoracic tergile. 



Each of these organs is composed of a lacuna 

 under the integu«ienls, and of a muscular contractile 

 membrane enclosing this lacuna. 



The membrane is convex towards the lacuna and 

 during contraction slrelches like a dia[)hragm and 

 becoming flattened acts as a suction pump. Elastic fl- 

 brillae, inserted normally to the surface, bring back the 

 membrane to its first or convex position when contrac- 

 tion ceases, that is during expansion. 



Opeiîings in Ihe walls of the lacuna conned it 

 with the vascular system of the elytra, and seconda- 

 rily with the thoracic, channels, on Ihe one hand and 



