92 Objects for the Microscope. 



or scales, varying in shape and colour with the species ; 

 and that some are so delicately ornamented with a tracery 

 that no unassisted eye can see that they form test objects 

 for the defining power of the microscope. 



Besides that use, we learn much from viewing a part of 

 a butterfly's wing as an opaque, and observing how the 

 scales are arranged on the membrane of the wing exactly 

 like the tiles on the roof of a house ; this is called being 

 " imbricated "; each scale furnished with a point at one 

 end which fits into a cup -like socket, attached to the skin 

 of the body or the membrane of the wing. When the scales 

 are rubbed off and transparent, we can better observe their 

 structure, and we have some excellent examples in the 

 slides numbered here. 



SCALES OF MOEPHO MENELAUS. 



Each scale or feather consists of three distinct laminae, 

 two external and coloured, the inner one a highly polished 

 colourless membrane, which reflects the light and increases 

 the brilliancy of the scale. The Morpho menelaus, a large 

 foreign butterfly of gorgeous blue, has striated scales, and 

 with very high power, each line is slightly beaded, giving 

 the appearance of transverse scoriae ; but to see this the 

 achromatic condenser must be used. 



SCALES OF POLYOMMATUS ARGUS, 



a British Butterfly common as the pretty blue butterfly of 

 the cornfield, or the seaside Downs ; has peculiar scales 

 shaped like a battledore with long handle, and the longi- 

 tudinal lines are swollen at intervals into rounded eleva- 

 tions, which give it a dotted appearance, except towards 

 the base, where a crescent-shaped cloud of minute pigment- 

 cells crosses the scale, and forms a distinguishing mark of 

 the species. 



SCALES OF HIPPARCHIA JANIRA, 



our little meadow brown Butterfly, which flits so merrily 

 about the long grass in June to October, laying its exqui- 

 site eggs upon the stems, from which a green striped 

 caterpillar emerges in due time. These are the scales of 



