lochh e a d] CA NA DIA N DEPA R TME.\ 'T 2 1 1 



The blacks, browns, yellows and dull reds of butterflies and moths, 

 then are produced chiefly by pigment; while all the brilliant metallic 

 colors, the iridescent blues and greens, and hosts of allied shades, are 

 due to the structural or physical make up of the scale-covering. The 

 patterns, varied and intricate, with lines and spots and bars, sharply 

 deliminated or softly merging into the ground color or into one 

 another, depend on the fact that the color units, the scales are so 

 small that by the juxtaposition of scales containing different pigments, 

 or varying slightly in structure, different colors may be produced 

 abruptly or gradually, depending upon the degree of regular arrange- 

 ment, in the higher moths and butterflies, of the short, rigid, little 

 scales, definite lines and sharp limits to spots and bars are possible. 

 In the lower fluffy moths where the scales are hair-like and irregularly 

 arranged such sharp deliminations of pattern parts are not always 

 possible. Thus the specialization of the scales, both as to structure 

 and arrangement, in the brilliantly colored and complexly colored 

 day-flying Lepidoptera is seen to be exactly connected with the spe- 

 cialization of color and pattern. 



We have carefully refrained from referring to the probable uses and 

 significance of the colors and patterns of the butterfly wings. That is 

 a subject which requires a paper to itself. But as a basis for any 

 study of the significance of color pattern among butterflies and moths 

 the first requisite is a knowledge of the actual mechanism of color 

 production, and this is what the present paper a 'tempts to explain. 



CANADIAN DEPARTMENT 



EDITED BY PROFESSOR W LOCHHEAD 

 The Macdonald College, St. Anne de Bellevue, Quebec 



The work along nature-study lines now being developed in Canada 

 and the support which this magazine Tias from the beginning received 

 from Canadian subscribers make it desirable that a department should 

 be edited by some one directly in touch with the work and workers. 

 Professor Lochhead, formerly of the Ontario Agricultural College and 

 recently appointed to the new Macdonald College, has consented to 

 undertake the labor of collecting and editing notes and articles deal- 

 ing with nature-study in Canada. Manuscripts should be sent 

 directly to him at the address given in the heading of this department. 



M. A. B., Managing Editor. 



