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. 



If Fif Pf Tf t'a. r<f Os.S\j 



x: 



>j 



'J'\ 







THE DENTITION OF SNAKES. 

 Fig. 138. — The skull of a typical non-venomous snake {Boa) and that of a typical venomous snake 

 (Crotalus) seen from the side and somewhat from above. 



W— Nasal. Pr/— Prefrontal. Fr.— Frontal. P/— Post frontal. Pa— Parietal. Pe— 

 Petrostral. Os — Supra-occipital. Sq — Squamosal. Q — Quadrate. H — Ear bone. Pt — 

 Pterygoid. Pj;— Pri'-maxilla. Mx — Maxilla. Pal — 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 



