S2Z 



BEITISH APHIDES. 



INTRODUCTION. 



A FEW remarks by way of preface to this second 

 volume of British Aphides may be permitted. 



And first the Author thinks some apology is due to 

 the reader for the large space occupied by the coloured 

 plates of this Monograph. It is felt that through 

 their assistance alone adequate ideas can be given of 

 forms which possibly hereafter, through the suppres- 

 sion of parts, or causes (so styled) evolutionary, may 

 be proved to be in a state of transition. Coloured 

 plates also enable us to mark the gradual deposition 

 of pigment within the integuments of the insects at 

 different ages, and to note the development of form 

 at various periods of the cycle of their persistence. 



It has been said that " you have no right to regard 

 that as a species which you cannot accurately describe 

 in words." If to this maxim we should add the con- 

 ditions of pictorial delineation of form and colour, the 

 truth perhaps would be more obvious; for all that 

 mere words can do in such a case is to enable us to 

 compare in a positive way what lies before us, and 

 le^ve negative evidence in great measure disregarded. 

 Word-painting may create grand poetic conceptions, 

 but cannot, we will say, realise the exact features of 

 a fine landscape and all its details. The work of the 

 scientific artist is more of a humble character, never- 

 theless in its'way it is creative, for through the eye 



VOL. II. 1 



