VI 
PREFACE. 
With respect to colour-representation, it must be remembered that some light is 
always lost by transmission through prisms and lenses. Enlarged figures of insects 
are liable to appear with less contrast than when seen of their natural size. It is 
not easy to concentrate sufficient daylight on an object, and artificial light, unless it 
be that from electricity, tends to obliterate delicate shades of blue and green. 
The author offers his best thanks to those, both at home and abroad, who have 
generously assisted him by loans of insects. Except through the good help given by 
others, this monograph would have lost whatever scientific value it may now possess. 
Amongst these efficient helpers have been the Rev. Canon W. W. Fowler, 
Mr. W. L. Distant, Mr. W. F. Rosenberg of Ecuador, Mr. Rippon, Mr. E. E. Green 
of Ceylon, Mr. J. O. Tepper of Adelaide, Mr. Chas. Lounsbury of Cape Town, and 
Dr. C. Aurivillius of Vienna. Particularly the author's thanks are due to Mr. 
W. F. Kirby, of the British Museum, for his assistance in overlooking proofs, and 
suggestions. The author also feels under great obligation to Professor E. B. Poulton 
for his valuable chapter on “ Suggestions as to the Meaning of the Shapes and 
Colours of the Membracidse in the Struggle for Existence.” 
Finally, for the interest shown by the author’s daughters in the subject, for the 
apt resetting of small insects more suitably for drawing, and for other assistance, the 
author expresses his affectionate recognition. 
Freedom of thought is a necessary condition of all scientific inquiry, which 
amongst other considerations includes the intricate problems of biology. 
Modern reflection more and more gravitates to the ancient postulate of a benevo¬ 
lent Creator of all material and vital energy. Lord Kelvin remarks, “ that there is 
nothing between absolute scientific belief in a creative power, and the acceptance of 
a theory of a fortuitous concourse of atoms. ... It is absurd to think that lapse 
of time could produce a living animal, much less the miracle of human free-will 
and thought.” 
Evidence of purpose appears through the pages of this memoir. The author 
hopes that in it something may be found which will add to our knowledge of nature, 
and tend, in Lord Bacon's words, “to the Glory of God and to the relief of man’s 
estate.” 
