OF THE GLANDS. 47 



maxillary gland. In those serpents in which is found, 

 besides the posterior teeth, a long one in the middle of the 

 jaws, the gland, at this point, has also a more considerable 

 volume, in order to supply this large tooth with a more 

 abundant liquor. In many other snakes, the maxillary 

 glands extend under the rostral plate, and unite from both 

 sides, but very often the rostral is divided from the maxil- 

 laries. The maxillary and mandibular glands, ranged 

 above the jaws, send into the mouth their secretions by 

 small excretory ducts, opening in the gums at the base of 

 the teeth. The duct of the large gland in serpents with 

 posterior grooved teeth, is very visible, and corresponds 

 exactly mth the groove which conducts the saliva into the 

 wound. Very often the maxillary gland is suspended by 

 a tendinous band to the articulation of the lower jaw. 



Besides this complicated salivary apparatus, common to 

 all serpents, we find in others a peculiar gland destined to 

 secrete a liquid, which, when introduced into the animal 

 frame, produces effects more or less deadly. This gland, 

 called poisonous^ because it is the characteristic of venom- 

 ous snakes, is shut up in veiy dense tendinous covering, 

 strong and firai to the touch, and ending posteriorly in a 

 narrow slip, which attaches it to the articulation of the lower 

 jaw. Anteriorly, this covering becomes narrow, and ends 

 in a pretty vdde duct, extending along the maxillary bone, 

 and descending to terminate in the orifice situate on the 

 anterior face of the base of the fang. In the real venom- 

 ous snakes, this duct is in folds when the long fangs are 

 recumbent, and has the capability of distension, and of ac- 

 commodating itself easily to the movements of the maxillary 

 bone. The interior of the venom-gland is divided into a 

 great number of minute compartments or cells, produced 

 by the meeting of their very thin walls at different angles.* 

 It is to this structure alone, totally different from that of 

 the salivary glands, that the secretion of the fluid called 

 poison is due, which has got its name from the deleterious 

 effects it is capable of producing in the animal economy. 

 It is true that the bite of the most harmless animals may 



* See MiJLLER, De penitiori Glandularum Structura. 



