Scales of Insects and Fish. 41 



Herald-moth, with, one conspicuous white spot on each 

 of its upper wings, shining like a star, or with the 

 peculiar brightness that this representation of it (Plate 

 III., fig. 1) would exhibit if we were to prick it with a 

 pin and hold it up to the light. On examining it with 

 the microscope, I found that this spot consisted of a 

 thick tuft of white scales, almost like a little brush, 

 and standing up much higher than the surrounding 

 parts of the wing (fig. 2). 



In like manner the scales of the Emperor-moth, 

 a large insect with an eye-like spot in each wing, are 

 rendered much more ornamental by being set sloping 

 upwards instead of nearly level. There is a beautiful 

 semi- transparency in the wings of this moth, owing to 

 the thinness with which its scales are scattered ; but 

 their sloping arrangement gives brilliancy at the same 

 time. It is, of course, difficult to represent it on a 

 flat piece of paper. The eye-like spots are each 

 about the size of fig. 3, and fig. 4 is intended for a 

 small part of one of them, magnified sixty diameters. 

 The colours are white, morone crimson, a sort of 

 straw-colour and black, a beautiful and harmonious 

 mixture. 



I have noticed another deviation from the plan of 

 nosaic work in the wing of a moth one of the tribe 

 of " Yellow Underwing." The wing is rather dingy, 

 but with a silvery gloss in some parts, which induced 

 me to examine it. I found that the scales themselves 

 were shaded. In one place, for instance, where the 

 wing is brown and white, the microscope showed that 

 instead of having rows of white scales and of brown 



