OF THE VENOM OF THE RATTLESNAKE. 



11 



It is proper to mention that almost all of these snakes had been in captivity 

 during periods of from two to eight weeks. 



It will be seen from this table that very little relation can be established between 

 the size and weight of the snake, and the weight of the gland, beyond the mere 

 fact of the general increase in the size of the organ, with that of the snake. 



The poison gland is invested with a double layer of white, and not very yield- 

 ing fibrous tissue. The two layers of this membrane are united at the base of the 

 gland, and becoming thinner anteriorly, they run off upon the duct, constituting 

 a portion of its thickness. Besides furnishing attachment for the anterior temporal 

 muscle, the outer layer of this capsule gives off three remarkable ligamentous 

 expansions which suspend and confine the gland. 



The posterior of these is a narrow, but strong ribbon of fibrous tissue, see Fig. 

 5, e, which runs from the posterior extremity of the gland to the articulation of 

 the jaw, where it appears by its continuation backwards, to constitute one of the 

 external ligaments of that joint. 



The second, which we shall term the suspensory ligament, lies behind the gland. 



Pig. 6. 



A. The Gland and Temporal Mdscles seen from above. — a, the gland ; 6, anterior temporal muscle ; c, suspensory 

 ligament of the gland extended ; d, duct, drawn from its position. 



B. Diagram of Duct and Gland — side view. — a, the venom gland ; b, the duct, at its curve ; c, the sphincter ; d, 

 fang ; e, superior maxillary bone. 



Fig. Q A, c, a little above its middle line. It arises as a fan-like expansion upon 

 the capsule, and finally narrows to one-third, and is inserted on the bony surface 



