. The anatomy, physiology, morphology and development of the blow-fly (Calliphora erythrocephala.) A study in the comparative anatomy and morphology of insects; with plates and illustrations executed directly from the drawings of the author;. Blowflies. 652 CIRCULATION OF THE BLOOD AND DORSAL VESSEL. own ostia, and the contraction of each accelerates the velocity of the moving fluid. The figures of the valves given by Verloren suggest that the flow of fluid into the dorsal vessel is due to the velocity of the axial stream, which undoubtedly acts as an injector and draws blood in through the os
. The anatomy, physiology, morphology and development of the blow-fly (Calliphora erythrocephala.) A study in the comparative anatomy and morphology of insects; with plates and illustrations executed directly from the drawings of the author;. Blowflies. 652 CIRCULATION OF THE BLOOD AND DORSAL VESSEL. own ostia, and the contraction of each accelerates the velocity of the moving fluid. The figures of the valves given by Verloren suggest that the flow of fluid into the dorsal vessel is due to the velocity of the axial stream, which undoubtedly acts as an injector and draws blood in through the ostia; but he does not apparently regard this as a factor in the circulation, or, if it occurred to him, he does not mention it. Graber [313] attempted an explanation of the diastole, which I am not sure I fully understand; but he says, after describing the passage of the blood through the narrow space between. Fig. 88.—.\ diagrammatic figure of the ostia. The narrow orifice between the ven- tricles, v", v', is supposed to act as an injector, drawing blood through the ostia, OS, in the direction of the arrows. the ostia : ' At the same time blood is sucked through the ostia.' The dilatation of the dorsal vessel is by no means easy to comprehend, lying as it does in the pericardial space. After the blood has been expelled and the muscular walls relax, there is no very apparent reason why the blood in the pericardial space should pass into its interior. The filling of the dorsal vessel cannot be due to pressure outside it, and it is not easy to discover any effective mechanism by which it can actively dilate. The fine fibres which connect the dorsal vessel with the pericardium no doubt may assist by causing a small quantity of blood to enter through the ostia, especially in the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resembl
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Keywords: ., bookcentury1800, bookcollectionbiod, bookdecade1890, bookyear1890
