n SHADOWS AND MARKINGS 57 



of the marking in definite directions in the intermediate 

 stages between longitudinal striping and spotting and trans- 

 verse striping ? 



I have permitted myself to express the supposition l " that 

 the fact of the original prevalence of longitudinal striping 

 might be connected with the original predominance of the 

 monocotyledonous plants, whose linear organs and linear 

 shadows would have corresponded with the linear stripes of 

 the animals ; and further, that the conversion of the striping 

 into a spot-marking might be connected with the develop- 

 ment of a vegetation which cast spotted shadows. It is a 

 fact that several indications exist that in earlier periods the 

 animal kingdom contained many more striped forms than 

 is the case to-day." The American fauna exhibits in many 

 respects a lower stage of evolution in the markings of its 

 members than ours ; it gives, therefore, at the present day an 

 idea of the condition of the ancient world referred to. This 

 supposition of mine is also supported somewhat by the fact 

 " that at present strongly spotted forms mostly occur in places 

 with spotted shadows, the longitudinally striped more in 

 grassy regions. Young slugs and caterpillars are often longi- 

 tudinally striped. Cross-marking is perhaps to be connected 

 with the shadows, for example, of the branches of woody 

 plants, thus the marking of the wild cat escapes notice 

 among the branches of trees." Others have previously 

 suggested such relations as that of the cross-striping of the 

 tiger with the shadows of the bamboos in which it lives. 



Weismann also has sought in the different markings of 

 the caterpillars of Sphingidse adaptations to their environment. 

 And w 7 hile he provisionally leaves out of consideration the 

 ultimate causes of the origin of any of these markings he 

 says, " Even the first commencement of striping must have 

 been useful, for it divided at once, to the eye of the observer, 



1 Variiren, etc. 



