196 COLOUR IN NATURE chap. 



to the markings. It is fitting, therefore, that at this 

 point, before passing from the Invertebrates to the 

 Vertebrates, we should consider for a little the mean- 

 ing and characters of patterns. We have again and 

 again encountered such types of coloration among 

 the Invertebrates, but when we pass to Vertebrates 

 we shall find that absolute uniformity of colour is 

 relatively rare, and that in most cases the markings 

 or patterns are the conspicuous features. We pro- 

 pose, therefore, to consider here first some of the 

 characters of the colour-patterns naturally occurring 

 in organisms, and then some suggestions as to their 

 meaning. 



The Patterns and Markings of Organisms 



Plants. — Among plants colour -markings occur 

 most conspicuously in flowers, for the artistic value 

 of foliage depends in the general case upon simple 

 colour contrasts between stem and leaves and upon 

 beauty of form rather than upon complexity of 

 marking. In flowers, as is obvious upon a moment's 

 reflection, the markings depend greatly upon the 

 form and character of the parts. Flowers in which 

 the floral envelopes consist of similar parts have these 

 parts similarly marked, as, for instance, the stripes or 

 markings on the petals of tulips, of geraniums, snow- 

 drops, and so on. Slight irregularities of colour are 

 associated with correspondingly slight variations in 

 structure, as seen in some of the so-called honey- 

 guides, such as the spot of dark colour in the flower 

 of the rhododendron. On the other hand, the more 

 complicated colour-markings are usually confined to 



