193 



n< T of ctiolin, ;ind do not In: until they are exposed t<> 



li.u'ht (or electric light), without which chlorophyll doe. not develop; 



and as metabolism . hlorophyll dish 



lea\in.u it- yellow con.st it nenl , xanl hophyll, which is very likely the 



1C substance as etiolin. 



hulcla sc.\-i(lltilii and ( '<ilost>ni<i sfntliitor blue in place of 



. Thc>c colors in these bed ' ruclural, and their \ 



are to be attributed to slight differences in the >t ructure ot 1 1 



l, rein grasshoppers occasionally become i>ink toward the close of 

 summer. \o e\])lanation has been offered for this phenomenon, t li 

 it may be remarked thai when grasshoppers are killed in hot water the 

 normal ^reen pigment turns to pink. 



These changes of color are apparently of no use to the insect, being 

 merely incidental effects of light, temperature or other inorganic 

 influences. 



