Manchester Memoirs, Vol. Iviii. (1914), No. . 9 



Indian Museum, has not confirmed Murchison's state- 

 ment. The white filaments attached to the specimens in 

 the Indian Museum were found to consist of fibrous 

 matter which not only refuses to melt but, on the con- 

 trary, decomposes when heated, does not dissolve in 

 naphtha, and under the microscope appears to consist of 

 minute particles of a filamentous nature. That observed 

 by Murchison melted on heating into transparent colour- 

 less wax, which was readily soluble in naphtha, crystallised 

 on cooling into acicular spicules, arranged in stellate 

 masses, such as is readily observable in the wax secreted 

 by Ceroplastes ceriferus. These observations seem to the 

 present writer to show that Murchison probably was not 

 dealing with P. marginella, but with an allied species. 

 In selecting material for analysis it is desirable to use 

 the distal two-thirds of the filaments as the basal portion 

 when amputated frequently comes away with portions of 

 the chitinous integument which is liable to give mis- 

 leading results. Kershaw" states that the waxy filaments 

 of the Australian Salurnis inarginellus, Guer. dissolve 

 instantly in spirit, and melt with heat, are of a waxy 

 nature, but a large part consists of hollow filaments or 

 hairs, much broken and interlaced, insoluble in either 

 spirit or potash, apparently much resembling in chemical 

 nature the hairs which project beyond the anal segment 

 of certain leaf-hopper nymphs. I am indebted to the 

 kindness of Professor A. Lapworth, F.R.S., for making an 

 analysis of the white filaments of the larvae of P. margi- 

 nella^ which he states are closely allied to Chinese white 

 wax in chemical composition. He remarks that it is freely 

 soluble for the most part in chloroform, but is sparingly 

 soluble in alcohol even when heated, but dissolves after 

 some hours boiling in methyl alcoholic potash. On pouring 



^- Loc. cit., p. 608. 



