George Albert Boulenger

“ The fatal venom which certain of these Reptiles possess has so impressed the mind of men, that for a long time snakes were primarily divided into poisonous and non-poisonous, a classi- fication in which the more important characters, derived from the general structure, and especially from the skull, were subordinated to the physio- logical. ”

“ Snakes may be defined as greatly elongate scaly Reptiles without limbs, or with mere vestiges of the hind pair, without movable eyelids, without ear-opening, with elongate, deeply forked tongue retractile into a basal sheath, with transverse vent and paired copulatory organs, and with the two halves of the lower jaw independently movable, connected at the symphysis by an elastic ligament. ”

“ Thus, in Southern Australia it might be stated that all snakes showing the regular nine large shields on the upper surface of the head are dangerous to man, whilst those with small shields or scales are harmless ”

“ The latter character alone distinguishes them from all Lizards, but no single Lizard possesses all the others in combination.
In their most highly developed form these Reptiles are adapted for rapid reptation and for swallowing prey much exceeding their own calibre; hence the bones of the skull, on which a prehensile function devolves, are loosely attached to the cranium by ligamentous elastic tissue, or articulated in such a manner as to permit a wide buccal expansion ”