OF THE VENOM OP THE RATTLESNAKE. 39 



the gland tissues would aflbrd u considerable amount of venomous fluid, manufac- 

 tured, as it were, artificially. 



This question divides itself naturally into two queries : — 



1st. Is the gland tissue poisonous? 



2d. Are infusions of the gland tissue poisonous ? 



At first sight, nothing seems easier than to answer these questions, by inoculat- 

 ing animals with infusions of the gland, or portions of its tissue. On direct expe- 

 riment, sources of fallacy at once appeared. The first of these was due to the 

 difficulty of clearing the gland of poison already contained in it, in the form of 

 venom, filling its smaller ducts. Supposing us to have eliminated this element of 

 doubt, and to have ready a gland tissue washed clear of its actual secretions, if 

 we should have in its secernent cells but a small amount of poison, it may not act 

 upon a large animal. On the other hand, if a very small animal be employed, the 

 reagent may pi-ove too delicate a test, and the animal die from a mere trace of the 

 venom remaining in the ducts, or even of the operation required to insert a whole 

 venom gland under its skin. 



Mqyeriment. — A large Crotalus, fifty-three inches long, was secured as usual, and 

 four drops of venom obtained from it. It was then replaced in its box, supplied 

 with a bath, and not disturbed during five daj^s, after which an attempt was made 

 to rob it of the poison formed in the interval. It yielded but one drop, although 

 it struck several times at the collecting vessel. Seeing this, and knowing, from 

 previous experience, that it might be retaining its venom, I placed within its jaws 

 a pigeon's thigh, freed from its feathers. The serpent bit fiercely, the animal dying 

 in twenty-nine minutes. A second pigeon having been plucked, so as to expose 

 the breast, the snake was allowed to bite it three times. It died stupefied, at the 

 close of an hour. 



A third pigeon was next arranged, so as to be bitten four times about the breast. 

 The snake, by this time, was very unwilling to use its fangs. The pigeon died in 

 two hours and a half. It is clear from these experiments, that in confinement at 

 least, the venom is formed but slowly, and that in the present case the gland was, 

 in all probability, well emptied of its juices. The snake's neck was next severed 

 about two inches below the head, and the glands of both sides rapidly removed. 



The ducts were cut away near to the gland, the gland tissue pressed between 

 two slips of board, and finally washed by repeated injections, and subsequent com- 

 pression, until at length the returning fluid brought awaj' with it no sediment. 

 The whole of one gland was then minced up with twenty-five drops of water, and 

 introduced under the skin of the breast of a pigeon. None of the usual local or 

 general evidences of Crotalus poisoning followed, and within fifty hours the wound 

 looked dry and healthy. After this time, an extensive slough took place above 

 the site of the gland. As the previous signs and appearances did not warrant the 

 idea that any poisoning could have taken place, I made several experiments to 

 learn how far the skin of the pigeon can be separated from subjacent tissues, with- 

 out endangering its vitality. These observations soon taught me that any foreign 

 tissue which raised the pigeon's skin for a circumference of more than three or four 

 lines, was apt to occasion a slough. 



