96 Bulletin de la Société Entomologiqiie d'Egypte 



insects in general by Emile Blanchard (Ann. Sci. Nal, 

 (H), IX ; 1(S48). 



This learned student writes (loc. cit. p. 382): — " In 

 all insects there is a dorsal vessel with a cardiac and an 

 aortal portion. This vessel is the centre of the circula- 

 tion. The cardiac portion is divided into compartments 

 or chami)ers, variable in number in difierent types. 

 These chambers are provided with lateral openings lor 

 the return ol' the blood. The aortal portion is destined 

 to carry the nourishing fluid towards the fore part ol" 

 the body. The blood having thus reached the head 

 spreads into all the inlerorganic spaces ; at thè same 

 time it runs into the lacunae placed near the origin ol' 

 the respiratory tubes and thus penetrates between the 

 tracheal membranes kept open at the base by a spiral 

 thread. The nourishing licpiid, carried in this manner 

 to all the organs between the two tunics of which the 

 respiratory tubes are composed, is separated from the 

 air column by but a single membrane; it is reoxygenated 

 duiing its actual passage. Thus the tracheae in their 

 perii)hery become real nutritive channels. The ])lood 

 flowing back into the inler-librillary s[)aces is ])rought 

 back to the dorsal vessel, by vessels formed of cellular 

 tissue but without menibianous walls." And on page 

 381; — "The tracheae in reality appear to us as vessels 

 carrying air and enclosed in blood vessels ". 



As is well known this theory was recei^ed with 

 hostility. JoLY of Toulouse and Lhox Dltolr among 

 others (1849), opposed it strongly. 



1 think that Blanchard, deceived by certain appear- 

 ances of his Prussian blue injections, exagerated some- 

 what the healing of his doctrine. It is also possible to 



