CHAPTER XIV. 



THE CIRCULATION OF THE BLOOD AND THE DORSAL VESSEL. 



1. THE CIRCULATION IN INSECTS GENERALLY. 



THE circulation of the blood is maintained by the pulsations of 

 the abdominal or ventricular portion of the dorsal vessel. Its 

 anterior or thoracic portion conveys the circulating fluid to the 

 head ; the blood is there poured into numerous sinuses between 

 the various organs, and returns by the great ventral sinuses 

 to the abdomen, and, after bathing and nourishing the organs 

 of the body, passes again into the ventricular part of the dorsal 

 vessel. The relations of the blood sinuses and the tracheal 

 vessels have been already alluded to (p. 367). 



Historical. Although Swammerdam [4] and Malpighi [148] 



Bibliography : 



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307. CARUS, C. G., 'Entdeckung eines einfachen Herzen aus beschleunigten 

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309. BOWERBANK, J., 'Observations on the Circulation of the Blood in 

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310. BOWERBANK, J., ' Observations on the Circulation of the Blood, and 

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311. VERLOREN, ' Me"moire sur la Circulation dans les Insectes.' Mdm. 

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312. MAYER, H., 'Ueber die Entwicklung des Fettkopers der Tracheen 

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313. GRABER, V., 'Ueber den propulsatorischen Apparat der Insecten.' 

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