310 MISCELLANEOUS OBJECTIONS TO THE [Chap. VII 



subject, which was not treated at sufficient length in 

 the former editions of this work. I will now briefly 

 recapitulate the foregoing cases. 



With the giraffe, the continued preservation of the 

 individuals of some extinct high-reaching ruminant, 

 which had the longest necks, legs, &c., and could browse 

 a little above the average height, and the continued de- 

 struction of those which could not browse so high, would 

 have sufficed for the production of this remarkable 

 quadruped; but the prolonged use of all the parts to- 

 gether with inheritance will have aided in an important 

 manner in their co-ordination. With the many insects 

 which imitate various objects, there is no improbability in 

 the belief that an accidental resemblance to some com- 

 mon object was in each case the foundation for the work 

 of natural selection, since perfected through the occa- 

 sional preservation of slight variations which made the 

 resemblance at all closer; and this will have been carried 

 on as long as the insect continued to vary, and as long as 

 a more and more perfect resemblance led to its escape 

 from sharp-sighted enemies. In certain species of whales 

 there is a tendency to the formation of irregular little 

 points of horn on the palate; and it seems to be quite 

 within the scope of natural selection to preserve all fa- 

 vourable variations, until the points were converted first 

 into lamellated knobs or teeth, like those on the beak of 

 a goose, — then into short lamellse, like those of the do- 

 mestic ducks,— and then into lamellse, as perfect as those 

 of the shoveller-duck, — and finally into the gigantic 

 plates of baleen, as in the mouth of the Greenland whale. 

 In the family of the ducks, the lamellse are first used as 

 teeth, then partly as teeth, and partly as a sifting appara- 

 tus, and at last almost exclusively for this latter purpose. 



