18 



INTRODUCTION. 



vading power of love in the continuation of species. Nor are 

 the raven or golden locks of the country maiden less cared for 

 as she trips over the lea, or the steps of her sweetheart less- 

 elastic as they hasten to meet each other at their appointed 

 trysting-place down the glen or thorny dell. Nor is the innate 

 blush on the cheek of modesty less deep when their lips 

 instinctive meet in the mutual kiss of true and pure first natural 

 love, although not always so faithful and true as the court* 

 ship and marriage of the birds, who choose their own partners, 

 and neither seek divorce nor break their marriage contract. 



Some authors say that the change of plumage is due to the 

 action of the air and sun wearing the edges of the feathers ; but, 

 like Mr Selby, I think the increased brilliancy is more owing to 

 an inherent principle in the bird and the feathers themselves — 

 like the blush on the cheek of modesty — enhanced by the time 

 of the year and the increased vitality of our feathered friends. 

 For the same vital principle which deepens the hue of the 

 cheek can deepen the hue of the feather. 



That there is an invisible fluid pervading the feather appears 

 in the striking difference in elasticity and brilliancy of colour 

 between the feather of a bird when alive and a short time after 

 death. In water-birds especially this principle of life in the 

 feather is strikingly apparent, as the plumage which is im- 

 pervious to water upon the living bird is almost immediately 

 after death subject to its effect. Then, why should not the 

 feather be influenced by the constitutional state of the bird ? 

 And as that is in the highest degree of vigour immediately 

 before the season of propagation, why may it not be shown even 

 to the extreme points of the circulating medium by a partial 

 variation of colour ? — like the blush on the cheek, or increased 

 lustre of the feather ? 



Changes in the colour of the hair are not less a matter of fact. 

 It has been recorded that one night of grief or fear has turned 

 the raven locks of man or woman grey, like the young grey- 

 haired girl, whose locks changed in a night while holding her 

 little sister up over the rustic bridge over which she had fallen. 

 And it is well known that the summer and winter coats of 

 many quadrupeds are different. For instance, the stoat-weasel 

 and upland-hare assume a winter's garb without any shedding of 

 their coat. Therefore it is quite possible that the edges of the 

 feathers may be shed (but not by a gradual process), and present 

 a brighter surface of the same colour, or of a different shade 

 altogether. In those birds where this change takes place, it 



