INTR OD UCTION. 2 5 



If any scientific eyes honour it with a glance, they will with 

 clemency remember that, with no scientific knowledge what- 

 ever to start with, I have had to grope my way unaided, 

 plodding over technicalities which in themselves were 

 studies ; and if, as no doubt is the case, any misappre- 

 hension of such technicalities has here and there crept 

 in and misinterpreted the true meaning, I anxiously trust 

 that the truth has not been altogether obliterated by such 

 obscurities. 



In conclusion, let me not omit a grateful tribute 

 to the invariable kindness of the heads of the Reading- 

 Room at the British Museum ; and for their assistance in 

 obtaining books of which I might never have known. The 

 kindness of Mr. Garnett extended even beyond the Reading- 

 Room ; for while I was invalided at the seaside, and could 

 only read, not zvrite, he translated and forwarded to me 

 some important pages from Lenz, a German ophiologist. 

 To him, therefore, the thanks of the reader are also due. 



In the choice of illustrations my aim has been rather 

 to exemplify a few leading features than to attract by 

 brilliantly-figured examples. Some of the woodcuts are 

 borrowed from Giinther's and Fayrer's works ; others I have 

 drawn faithfully from natural specimens; but in them all 

 I am indebted to the kind and patient work of Mr. A. T. 

 Elwes in reproducing my own imperfect attempts. And as it 

 was impossible to draw a snake /;/ action from life, or to 

 witness a second time the precise coils or movements which 

 had at first struck me as remarkable, the composition of 

 some of these subjects was by no means an easy one. Our 

 united efforts have been to represent the natural actions as 



