Séance du 17 Novembre 1920 89 



on Ihe olher with the aoiin. Kach coiilracUon ol' lh(> 

 liicsolergal organ [ìumps llie Ijlood flowing back f'roiìi 

 tlu' elytra, and secondarily the blood of llie (boracic 

 cbannels, lo drive il into Ibe aoila wbile tiie melalergal 

 organ ads similarly on tbe blood (lowing back IVoni 

 tbe wings. 



BaodiKii observed the presence of pnlsalile organs, 

 bolli nieso- and meta- thoracic, not only in Dijli.sciis 

 bnl also in the Sphingi(h\c - in Sphinx convolnuli and 

 Mdcrofjlossa stellataruni - then in Cossus ligiìiperdd, 

 üi'cticiis ih'rriicivorus, Gnillusc(iiìi/>eslris, Tdhaniis bovi- 

 niis, TipuUt, Panorpti and several Ephemoridae. 



In the Lepidoptera, tbe mesotergal organ of which 

 is remarkably large, tbe efferent branch joins the 

 thoracic aorta where this vessel forms a looj) turning 

 upward towards the surface. The latest men.oir of 

 Buor.HKii (Feb, 1919) gives on page 107, a sagittal section 

 of the Convolvulus Hawk-molh which is most instruc- 

 tive on this point. The curve in the aoila of the 

 Lepidoptera pointed out j)y Blik.kss in bS81, Ihongb 

 pre\iously unexplained, exists no doubt on account 

 of Ibis arrangement. 



Jankt (190()) described a pulsatile organ in the 

 thorax of winged ants. According to Biux.her, I)ri:n- 

 KELFoiiT (1910) and Ohkhlk (191;}) caught sight of the 

 tiioracic pulsatille organs in one of the l'^[)hemeridae 

 and in Dijliscus respectively. 



Alhough Mantis and Einpusn ha\e noi yet been 

 examined for these sjiccial organs these fads make 

 it highly probal>Ie thai Buocher's organs exist also in 

 tlie Mantidae and jilay a \ery important part in tl^e 

 iinrolding of the wings. 



