INTRODUCTION. 15 
In alluding to the “venom toad” as “mark’d by the 
destinies to be avoided,” Shakespeare probably only treated 
it as other writers had done before him, and, without any 
personal investigation of the matter, ranked it with the 
viper and other poisonous reptiles, when in fact it is per- 
fectly harmless. 
The habit which the snake has, in common with other 
reptiles, of periodically casting its skin or slough, is fre- 
quently alluded to in the Plays, where that covering is 
sometimes called “the enamell’d skin” (Midsummer 
Nights Dream, Act ii. Sc. 1); at other times the “ casted 
slough” (Henry V. Act iv. Se. 1, and Twelfth Night, 
Act iii, Sc. 4); and the “shining checker'd slough” 
(Henry VT, Part II. Act iii. Sc. 1). 
It is difficult to say why the Adder is supposed to be 
deaf, unless because it has no visible ears—but then the 
term would apply to other reptiles. Shakespeare has 
several times alluded to this. In the Second Part of King 
Henry VI, Act iii. Sc. 2, Queen Margaret asks the 
King,— 
“ What, art thou, like the adder, waxen deaf?” 
And in TZvoius and Cressida, Act ii. Sc. 2, Hector 
says to Paris and Troilus,— 
“ Pleasure and revenge 
Have ears more deaf than adders to the voice 
Of any true decision.” 
