On the anatomy of a new species of pentastoma found in the lung and air-sac of an Egyptian cobra / by George Harley.

  • Harley, George, 1829-1896.
Date:
[1857]
Catalogue details

Licence: Public Domain Mark

Credit: On the anatomy of a new species of pentastoma found in the lung and air-sac of an Egyptian cobra / by George Harley. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    very top of this immensely long duct. It may be said that the spermatozoa could find the way up themselves. That I admit might be the case if they were fully developed, and consequently moving filaments; but it would be impossible for them to get up in the un- developed condition in which some of them are found in the pouches. Besides this, if they were injected into the vagina, why did they not impregnate any of the ova on their passage up? Impregnation is distinctly seen to have taken place from above downwards, not from below upwards, or in any irregular manner. The only satisfactory way of accounting for the presence of sper- matozoa in different stages of development in the copulatory pouches, supposing that they were not generated there, would be to find a channel by which they might enter without having to pass through the 40 inches of oviduct. Now I have carefully searched for such a channel and can find no trace of one. Neither can I find any open- ing into the animal near to the spermatheca except the mouth, and I do not think any one will consider that a likely door for them to enter at. I admit that my not being able either to detect a tube or an open- ing into the spermatheca does not incontrovertibly prove that no such tube or opening exists. But I think that fact taken in con- nexion with the others, especially that of the spermatic filaments being found in various stages of development in the pouches, is tole- rable evidence in support of the idea that the organ containing the spermatozoa is the one which generated them. And until we hear some more conclusive arguments on the opposite side, we may con- sider ourselves justified in regarding the spermatheca as testicles, and calling the entozoon a true hermaphrodite. In conclusion, I have a word to add regarding the habits of the entozoon I have been describing. I found two of them with their heads projecting through the air-sac of the Cobra, and firmly fixed by their prehensile booklets to a large blood-vessel; from which I conclude that they feed directly upon the blood of the animal they inhabit. They appear to be blood-suckers in the strictest sense of the word. In order to get to the blood-vessels to which they anchor themselves by their hooks, the worm has to pierce the surrounding tissues, and the hooks are no doubt made retractile into the de- pression in order to enable the animal agaiu to withdraw its head after it has finished its meal. I found in the collection of Dr. Sharpey a fine specimen of an entozoon closely resembling the one I have been speaking of (PI. XLVI. fig. 3) ; the only difference being that it is shorter and thicker, has only nineteen strong projecting rings instead of twenty- seven, and that its tail is conical and not cleft; farther, that the vagina is about a line in front of the anus. Unfortunately no history is attached to this specimen.