310 



VENOMS 



above the membrane of the palate, which may contain | c.c. 

 of venom, and three or four conical, curved teeth, with the convex 

 surface in front, as in the fangs of snakes. The teeth are not 

 pierced by a central canal, and the venom flows between them and 

 the mucous membrane of the palate, which forms a sheath. The 

 latter is withdrawn to the base of the teeth, while they are pene- 

 trating the tissues. The teeth are mobile ; they are articulated 

 with the palatine bone, in which they are inserted in small depres- 

 sions, and a resistant fibrous tissue serves as the means of union. 



-2j ^-v^f^\^ v 1 ^^\_c ■ 



Fig. 120. — Murcena moringa (Tropical Atlantic). (After Savtschenko.) 



They can be deflexed backwards against the mucous membrane of 

 the palate ; in this position the first, second and fourth tooth (when 

 the latter exists) disappear completely between the folds of the 

 membrane. The third tooth normally remains erect, and it is this 

 by which wounds must in most cases be inflicted. None of these 

 teeth can be protruded beyond the vertical. 



In addition to the palatine teeth there are, among the groups of 

 maxillary teeth, several mobile teeth, which are connected with the 

 poison-reservoir. 



Besides its toxic action the venom of MurcEiia has manifest 

 digestive properties, and, in the case of a fish which has been dead for 

 some little time the gland is no longer to be found, since its walls 

 have undergone a rapid autodigestion. 



