PROTECTION OF EGGS. 83 



It may appear a little paradoxicalj though the doc- 

 trine is sound, to assert that down and similar ma- 

 terials are nearly as well calculated for protecting an 

 animal from excessive outward heat as from severe 

 cold. This, however, has been long well known as a 

 fact to the Neapolitan peasantry, who convey snow 

 from Mount Vesuvius to Naples in the summer for the 

 purposes of luxury : they preserve it from melting by 

 covering it with chaff and wool. It may not be out 

 of place to remark that instances of this occur among 

 insects, precisely similar to what we have just detailed 

 respecting the gypsey moth. The brown-tail and the 

 golden-tail moths {Porthesia aiirijlua, and P. Chry- 

 sorrhcea, Stephens), whose caterpillars spin them- 

 selves a warm nest before the setting-in of the winter 

 colds,* seem no less careful to protect their eggs from 

 the summer heats of July and August, at which time 

 they are deposited. The down with which they are 

 furnished for this purpose grows upon the tail of the 

 female moth, in form of a thick tufl or brush, of a 

 shining silky gloss, and of a different colour from the 

 short hair on the body. It may be remarked that 

 moths have only a mouth tube for sucking honey, and 



Females of the brown and gold-tailed moths, showing the bunch 

 of down on the tails. 



* See ' Insect Architecture,' p. 329 — 331. 



