SCALES OF PONTIA BRASSICA. 97 



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 sea-side Downs; has peculiar scales 

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

 tudinal lines are swollen at intervals into rounded elevations, 

 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 iu due time. These are the scales 

 of its brown wings, most excellent test objects, and giving 

 different markings. When dry, or in Balsam, or when 

 viewed by oblique or direct light, we see that the rounded 

 end is toothed, and bears a brush-shaped appendage. 



SCALES OF PONTIA BRASSICA. 



The common Cabbage Butterfly, whose history is too 

 well known to need remark ; the earliest and latest of our 

 Summer friends and garden enemies. There are several 

 shapes in the scales of its wing, a very long and slender one, 

 and some more of the battledore "shape, and heart-shaped, 

 with beautiful strise. Observe also a portion of the mem- 

 brane, where the scales or feathers are rubbed off. The 

 apertures into which they are fixed are little cups or tubes, 

 the orifices of which are set backward ; and around each 

 are radiating folds of the upper membrane, giving them a 

 star-like appearance. 



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