MY NEW IDEAS 401 



while his mental faculties improved. This paper was greatly 

 admired by Mr. Darwin and several other men of science, 

 who declared it to be entirely new to them; but owing to its 

 having been published in one of my less known works, 

 " Contributions to the Theory of Natural Selection," it 

 seems to be comparatively little known. Consequently, it still 

 continues to be asserted or suggested that because we have 

 been developed physically from some lower form, so in the 

 future we shall be further developed into a being as different 

 from our present form as we are different from the orang 

 or the gorilla. My paper shows why this will not be ; why 

 the form and structure of our body is permanent, and that it 

 is really the highest type now possible on the earth. The 

 fact that we have not improved physically over the ancient 

 Greeks, and that most savage races — even some of the lowest 

 in material civilization — possess the human form in its fullest 

 symmetry and perfection, affords evidence that my theory is 

 the true one. 



3. In 1867 I gave a provisional solution of the cause of 

 the gay, and even gaudy colours of many caterpillars, which 

 was asked for by Darwin, and which experiment soon proved 

 to be correct. This is referred to in chapter xxi. of the present 

 volume, and is fully described in my " Natural Selection and 

 Tropical Nature," pp. 82-86. The principle established in 

 this case has been since found to be widely applicable 

 throughout the animal kingdom. 



4. In 1868 I wrote a paper on "A Theory of Birds' 

 Nests," the chief purport of which was to point out and 

 establish a connection between the colours of female birds 

 and the mode of nidification which had not been before 

 noticed. This led to the formulation of the following law, 

 which has been very widely accepted by ornithologists: 

 When both sexes of birds are conspicuously coloured, the nest 

 conceals the sitting bird; but when the male is conspicuously 

 coloured and the nest is open to view, the female is plainly 

 coloured and inconspicuous. No less than fifteen whole fami- 



