12 PHYSIOLOGY AND TOXICOLOGY 



to the inner side of the gland. This ligament is remarkably strong and unyield- 

 ing ; it supports the gland perfectly, and even acts as a passive antagonist to the 

 force exerted by the anterior temporal muscle, while at the same time it shelters 

 the large nerves which emerge beneath it from the skull. 



The third attachment of the gland is by means of a fascia, which forms a strong 

 expansion upon the external pterygoid muscle, Fig. 3, c, and then runs off 

 laterally, to be inserted upon the outer capsule of the gland. This connection is 

 principally with the lower and anterior portion of the gland. Its object will attract 

 our attention in another place. 



Anteriorly, and along its upper edge, the gland is secured by areolar tissue, con- 

 necting it with the edges of the temporal fossa, and the posterior edge of the orbit. 

 At the extreme anterior point of the temporal muscle, however, a portion of its 

 proper aponeurosis is gathered into a band, to which run also similar fibres from 

 that part of the capsule of the gland which lies below the muscle. This collection 

 of rather delicate fibres — for in the Crotalus it can scarcely be called a tendon — 

 runs forward above the flexure in the duct, and below the eye, to lose itself on the 

 edge of the fossa, and about the base of the superior maxillary bone. Soubeiran 

 describes in the Viper a tendinous insertion of the anterior temporal, as taking the 

 track here described. I have been unable to discover this insertion in any of my 

 dissections of the Crotalus. 



In almost every account of the anatomy of the Crotalus, and in nearly all of 

 the essays upon the effect of its venom, some allusion is made to a sac, or reservoir 

 of poison. Strictly speaking, there is no such organ, and the only provision for 

 the accumulation of venom is to be found in the duct, and its enlargement within 

 the gland. 



The duct expands somewhat suddenly, as it enters the gland, and being directed 

 backwards and a little upwards, forms an irregularly-rounded cavity, which runs 

 nearly the whole length of the gland. Into this receptacle, the smaller ducts of 

 the gland empty their contents. From the sides of this cavity there run obliquely 

 upwards, and a little backwards, from five to eight layers of white fibrous tissue, 

 which, lying transversely to the long axis of the gland, separate its secreting 

 portion into lobes, which narrow as they approach the central cavity. The septa 

 here described are finally lost in the capsule of the gland. On their passage out- 

 wards, they send off numerous branches and thin sheets of tissue which proceed 

 upwards, for the most part, but also across the lobes, and thus involve the 

 secernent structure in a supporting scaffolding, of the firmest possible character. 



The gland so constructed, resembles very strikingly, in section, the appearance 

 of a small testicle. Its color is usually of a pearly or gray-white within, except 

 under certain pathological conditions, when it is full of blood, and presents exter- 

 nally a darkly-mottled look. 



The intimate structure of the poison gland resembles very closely that of the 

 typical salivary glands. From the open space at the base of the gland, a number 

 of ducts run up into its substance, and dividing, pass towards the periphery. The 

 direction of these ducts is, for the most part, backwards and upwards. Owing to 

 the strength of the fibrous bands which traverse the gland, and to the extreme 



