232 JOTTINGS ABOUT BIRDS. 



with Plovers, Terns, Gulls, &c., which may possibly 

 have been implanted on the egg during the concep- 

 tion and pregnancy. It is a curious and noteworthy 

 fact, that the eggs of such birds as are nocturnal, or 

 frequent holes, caves, and similar gloomy haunts, 

 where all sense of colour is lost, are in the majority 

 of instances white ; whilst in such birds, belonging 

 to groups in which the eggs are highly coloured, as 

 incubate in covered or gloomy sites, there is a strong 

 tendency to deterioration in the vividness and in- 

 tensity of the markings, or even for them entirely 

 to disappear. Protective colouring of plumage, or 

 what we are apt to call Protective Colour, may have 

 been influenced in a similar way. The peculiar 

 birthmarks impressed on unborn children through 

 various accidents or frights to the parent at the 

 later stages of pregnancy seem in a measure to 

 confirm this theory of colour on the eggs and 

 possibly the plumage of birds. I also wish to state, 

 that most of the exceptions to the general rules 

 respecting the colour of birds' eggs illustrate very 

 forcibly what I have endeavoured to impress upon 

 the reader respecting the importance of keeping in 

 view community of origin in investigating this 

 subject. Broadly speaking, it is only amongst the 

 more highly specialized forms of bird-life that we 



