. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 172 I5RKNTON R. LUTZ cardinal sinus, which was slit lengthwise exposing the nerves on its floor. This involved some loss of blood, and care was taken to keep the fish in a horizontal position to prevent sucking air into the heart. A bloodless method, described by Hemmeter (1912), of exposing " the ramus cardiacus " was found not to be practicable on the 300 gram fish, especially since the heart of Scyllium canicula receives not only a branch from the visceral trunk of the vagus but also a branch from the fifth bran
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 172 I5RKNTON R. LUTZ cardinal sinus, which was slit lengthwise exposing the nerves on its floor. This involved some loss of blood, and care was taken to keep the fish in a horizontal position to prevent sucking air into the heart. A bloodless method, described by Hemmeter (1912), of exposing " the ramus cardiacus " was found not to be practicable on the 300 gram fish, especially since the heart of Scyllium canicula receives not only a branch from the visceral trunk of the vagus but also a branch from the fifth branchial nerve (4th branchial division of the vagus). The first large sympathetic ganglion was exposed when necessary by opening the abdominal cavity. Since this ganglion lies within the posterior cardinal sinus, the latter must be opened with considerable unavoidable loss of blood. RESULTS Scyllium canicula was found to be very resistant to experimental procedures out of water when the gills were perfused. A preparation with the brain destroyed anterior to the optic lobes, the cord pithed posterior to the third vertebra, and the pericardial chamber opened, gave good cardiac and respiratory reflexes for over twenty-four hours. The laboratory temperature was about 14° C. When the anterior cardinal sinuses were opened, involving considerable bleeding, the. FIG. 1. Reflex cardiac and respiratory inhibition after transection of the ventral aorta. Forebrain and cord from the fifth vertebra destroyed. In this and subsequent figures the uppermost tracing is the heart record (//), the middle is respiration (R), and the lowest is the signal and time record. The large divisions are ten seconds. A, right fin pinched 21 minutes after transection of the aorta. B, gill perfusion stopped and started 31 minutes after transection. preparation remained experimentally useful for about two hours. If in addition to the above procedures the abdominal cavity was entered and the posterior cardinal sinus
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
