69 



CHAPTER XV. 



Moths' Scales. 



Under the microscope, the dust-like particles which are 

 removed by the finger when the moth's wing is touched 

 are more or less triangular-shaped plates pointed at the 

 end of their attachment to the membrane of the wing, and 

 widening out at the extremity of their lengths into either 

 serrated edges, as in the case of Antherma yama-mai, 

 Plate L., Figs. 5 and 6, or long digitate processes or spikes, 

 as in Actios Selene, Plate L., Fig. 4, giving in the various 

 species a most interesting variety of shapes, from the narrow 

 fusiform appearance in Attacus Cynthia, Plate XLIX., Fig. 5, 

 to the broad scales of the Tusser moth, Plate XLIX., Figs. 2 

 and 3, which are not unlike the shape of a bat-wing burner. 

 The scales, as they rest in situ on the moth's wing, 

 overlap each other with great regularity, like the tiles of a 

 roof, and somewhat analogous to the imbrications observable 

 under the microscope in the fur and wool of many animals. 

 I have had drawings made of the scales of some of the 

 species the silk of which is likely to come into more or 

 less extended use. 



The first 24 diagrams have been drawn from the 

 microscopic appearance of the scales when magnified 

 140 diameters, all being taken from that part of the 

 moth's wing indicated in Plate XXIII., Fig. 2, except the 

 following : — 



Bombyx mori (Plate LII. Fig. 3). 

 Actios Selene ,, „ 6). 



Anthercea rnylitta „ „ 4). 



Anthercea yama-mai (Plate LII. Fig. 5). 

 The scales represented in these four diagrams are taken 

 indiscriminately from all parts of the wing. 



The object of this inquiry is to show the structual 

 differences of the scales of the various species of the Indian 

 silk-producing Lepidoptera. I cannot say that I have dis- 

 covered sufficient divergence iu form corresponding with 

 specific differences in the moths, but there is no doubt such 

 divergence is very wide, and sufficient to distinguish the 

 genus Attacus from that of Antherma. 



The size of the scales is not in proportion to the size of 

 the moths, as may be seen from the scales of A nthercea 

 mylittahemg broader than those of Attacus Atlas, although 

 the expanse of wing in the Atlas moth is 4 to 5 inches 



