INTRODUCTION. 



ON THE PROTECTIVE COLOUR OP EGGS. 



[This chapter has been written for me by Mr. Ohables Dixon, and is sufficiently 

 elaborated to post my readers up in the questions which have arisen on this subject since 

 it has been regarded from the evolutionist point of view. It is, of course, partly based 

 upon Darwin (' Descent of Man,' ii. p. 166) and Wallace (' Natural Selection,' pp. 211, 231), 

 who have endeavoured to explain, by the laws of Natural Selection, the facts (long 

 ago remarked by Gloger * and others) respecting the colour of eggs. 



The results of the investigation are not quite so satisfactory as might have been 

 expected. There are so many cases which cannot be explained by protective selection, 

 that the student, not being able in this instance to fall back upon sexual selection, is 

 obliged to assume that many effects are the results of extinct causes. To my mind they are 

 suggestive rather of other powerful factors in addition to protective and sexual selection. — 

 H. S.] 



Oology has until lately been a much neglected science. Looked upon as 

 an occupation which has for its object the mere collecting, labelling, and 

 arranging in a cabinet the eggs of birds, or threading them on strings like 

 beads, or^ worse still, sticking them on cards in all kinds of fantastic 

 patterns, egg-collecting has long been regarded as a schoolboy's hobby, 

 and quite beneath the dignity of the man of science. But since the 

 great discoveries of those illustrious naturalists Charles Darwin and 

 Alfred Russel M'allace have placed the study of natural history on a 

 different basis, and completely revolutionized scientific research, oology 

 may be said to have slowly risen from a schoolboy's pastime or a collector's 

 craze to a science so fascinating and so instructive as to claim the careful 

 attention of many of our ablest naturalists. Such hitherto despised objects 

 as birds' eggs have a tale to tell quite as interesting as that of any other 

 object in the organic world ; they have a history to reveal which assists 

 in pointing out the line of march which organic life has taken from its 

 earliest dawn to its present endless and varied ramifications. But a study 

 of eggs cannot be made satisfactorily without including the birds ; the 

 two subjects are inseparably linked together, and it is necessary to have 

 the bird and its life-history before us when studying the egg with its 



* In the ' Edinburgh Journal of Natural and Geographical Science' (i. p. .303), published 

 in 1830, a short r^sum^ of Qloger's paper of the previous year is given, translated from the 

 < Verhandlungen der Gesellschaft naturforschender Fremide in Berlin.' 



VOL. !!• b 



