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Show 360 PROF. W. N. PARKER ON THE [Jutie 19, and he simply conjectures that the seat of the virus is in " the pulpy sheath of the spine." The most important observations on the subject which have been made by any English naturalist are undoubtedly those of Byerley (3), which appeared in 1849, but which have not been credited by many subsequent authors. Byerley correctly describes and figures transverse sections of the opercular and dorsal spines, as well as the position of the glands in connexion with them. In examining the microscopic structure of the glands, he simply scraped a portion out of its groove with a needle and mounted it in water, so that it is not to be wondered at that in this respect his conclusions are far from accurate ; the " tubes," " sacculi," and "follicles" which he describes are quite imaginary. H e was unable to make out any duct, and mentions that the integument completely covers even the points of the spines in a normal condition, but that they are rarely seen thus, as they usually protrude for some distance from their loose sheaths. His explanation of the manner in which the secretion is injected into the wound is that when the spine is driven some distance forcibly into the flesh, the integument which covers it yields to the pressure of the wounded parts, and is thus thrust downwards towards the base of the spine. In this way the gland must be squeezed with some violence, and its contents pass along the grooves of the spine into the wound. This unsatisfactory account of the structure of the glands led Giinther (13) to doubt the accuracy of Byerley's conclusions, and to consider that the substance which he took for a gland was simply " the poisonous fluid itself, coagulated or hardened by the action of the spirits in which the specimen had been preserved." Giinther, moreover, states elsewhere (11) that "no special poison-organ has been found in these fishes, but there is no doubt that the mucous secretion in the vicinity of the spines has poisonous properties." (Comp. also 12.) Day (9) also states that nothing certain is known, either as to the seat of the poison or the manner of its ejection, and mentions that " it has been surmised that the virus is a secretion or excretion from the mucous surface of the loose skin which covers the spines." Couch (5) describes "the skill and precision with which the formidable spine of the neck (of T. draco) is directed to an object of fear," and, without mentioning Byerley at all, states that " the spines of the dorsal fin have also been an object of dread ; but in these cases the wound is only accidental, and the fish does not employ them for any purpose of injury or defence." He also states that " it is certain that no exudation or discharge of a poisonous fluid proceeds from this projecting (opercular) spine." Yarrell (22) quotes Couch, and mentions that the Weever " strikes with great force either upwards or sideways. Pennant states that he has seen it direct its blows with as much judgment as a fighting cock." Macalister (16) simply states that the Weever "is commonly thought to inflict poisonous wounds;" and Seeley (18) speaks of the |
