98 Colouration in Animals and Plants. 



But if animals thus learned to paint themselves in definite 

 patterns, we might expect that when called upon to decorate for the 

 sake of beauty certain parts not structurally emphatic, they would 

 adopt well-known patterns, and hence arose the law of repetition. 



But with wider experience came greater powers, and the necessity 

 for protection arising, the well-known patterns were enlarged, till an 

 uniform tint is produced, as in the Java pig, or some repeated at the 

 expense of others, as in the civets. But so ingrained is the tendency 

 to structural decoration that even where modification has reached 

 its highest level, as in the leaf-butterflies, some trace of the plan that 

 the new pattern was founded on is recognisable, just as the rec- 

 tangular basis can be traced in the arabesque ornaments of the 

 Alhambra. 



The pointing out of this great fact has seemed to us a useful 

 addition to the great law of evolution. It supplements it; it gives a 

 reason why. 



Could he who first saw these points have read these final pages, 

 it would have lightened the responsibility of the one upon whom the 

 completion of the work has fallen. But he died when the work was 

 nearly finished. The investigation is of necessity incomplete, but 

 nothing bears such misstatements as truth, and though specialists 

 may demur to certain points, the fundamental arguments will 

 probably remain intact. 



