86 Mr. A . D. Taylor. 



procured will starve sooner than eat anything foreign to their 

 nature. 



I believe myself, and everything I have read as to cause of 

 colour does not change my opinion, that, firstly, the natural 

 colors of both larva and moth exist in the cells of their bodies 

 and are produced when wanted, for we see that when the 

 larva first leaves the egg it has all its natural colors upon 

 its skin. With every after-change of skin the same colors are 

 reproduced underneath the old skin, and appear as the old 

 skin is gradually rejected. Again, when the larva is passing 

 through its last final transition into the pupa, and has thrown 

 off its now somewhat faded skin (for nearly all larvae seem to 

 lose their bright colours before their last change), it leaves the 

 naked body of the still living insect colorless, yet the full colors 

 of the future butterfly may be seen through the pupa case 

 some hours before the insect emerges, the pupa case of most 

 butterflies becoming semi-transparent during this last process 

 of transition. 



Some authors have thought that some of the colors are 

 produced by the scales being placed one over another, two 

 or three combining to form a certain color, but this can 

 only happen on certain parts. As a rule the scales are placed 

 singly in rows, one partly lying over another like slates. A 

 portion of the Buff Tipped Moth (Pygara Bucephalae) well 

 represents this arrangement. An article in the " Micrographic 

 Dictionary " confirms my ideas upon the cause and arrange- 

 ment of color. It states that the colors of the scales of insects 

 arise partly from iridescence, partly from the presence of 

 pigments ; in general, the brilliant colors depending upon the 

 former, and the more sombre upon the latter ; the darkness of 

 the longitudinal striae is caused by refraction : for scales con- 

 taining no pigment appear perfectly white by reflected light, 

 although the striae may be very dark. 



The variation in shades of colors and in the breadth and 

 intensity of markings, is easily accounted for ; great variations 

 of this kind occur mostly among the moths, and in those 

 species whose larvae feed upon a variety of food plants. This 

 is one cause, but we may also find another and a very simple 

 one. The eggs of moths are laid in considerable numbers, 

 and those which are first impregnated appear similar to their 

 parents ; afterwards, in succession, the remainder of the brood 

 will vary in breadth and intensity of both markings and colors. 

 The same thing happens with plants, seeds procured from any 

 plant, even of one that has not been affected by cross fertiliza- 

 tion by insects, will not produce plants all of the same colors 

 and character as the parent, but varieties both of color and 

 excellence. The insect shown by Mr. Lovett I think was 



