344 



THE SNAKES OF SOUTH AFRICA. 



Racemose Glands because the cells are clustered together like 

 a bunch of grapes — racemose meaning " arranged in grape-like 



A STUDY PLATE FOR SCIENTIFIC STUDENTS. 



Afx Pal 



^ ( ' 



' yojiiii-''"'' 



■^T- 



KPrf Fr If To. ^2 Oi 





■P<d j,^ jy J>f./ 



A ^^ 



THI-: DENTITION OF SNAKKS. 

 Fic. 1 18.— The skull of a typical non-venomous snake (Boa) and that of a typical venomous snake 

 {Lrolalus) seen from the side and somewhat from above. 



AT— Nasal. Pr/— Prefrontal. /•>.— Frontal. /V— Post frontal. Pa— Parietal. Pe~ 

 I etrostral. Os— Supra-occipital. Sy— Sauamosal. Q— Quadrate. //—Ear bone. Pt— 

 Pterygoid, /'jr— Prf-maxilla. M*— Maxilla. Pa/— Palatine. Tr— Transverse bone, i— 

 2 — 3 — Bones of lower jaw. 



clusters." These venom glands were once upon a time ordinary 

 salivary glands, and under that mysterious law of God which 



