TRANSPARENT GELATINE SHEET, 141 



protective than a plain dark under side. I have, indeed, often 

 found that V. io, for instance, maj' appear as one of the most 

 conspicuous of insects by its black-brown under side. Perhaps 

 the (polymorph !) A. levana with its next relatives comes very near 

 picturing to us what the ancestral form of the Vanessid^e was 

 like. If, then, the ancestors of levana were also " the ancestors 

 of V. urtica and V. io " (see antea, pt. 2, p. 58), then the latter 

 species would have separated (1) from levana (which hyber- 

 nates in the pupal stage) hy adopting the habit of hyhemating in 

 the imago stage, and (2) from each other by different reaction to 

 climatic influence (Standfuss), V. urticce remaining smaller and 

 many-brooded under temperature conditions which leave the 

 larger V. io single-brooded. 



(To be continued.) 



TRANSPARENT GELATINE SHEET: A MEDIUM FOR 

 MOUNTING THE SMALLER COLEOPTERA. 



By F. H. Moore. 



The preference which coleopterists show for pinning their 

 specimens, whenever size permits, argues a defect in the carding 

 method. 



An obvious disadvantage of carding is the concealment of the 

 insect's ventral side, and since pinning is out of the question for 

 a vast number of small Coleoptera, the advantages of a trans- 

 parent medium for mounting must be evident ; indeed, for 

 species bearing peculiar ventral characters, such a medium 

 becomes very necessary. 



Now a transparent gelatine mount permits of a clear inspec- 

 tion of one's specimens dorsally and ventrally, and obviates the 

 risks to which fragile insects fixed on pins are exposed. The 

 material is exceedingly clean and easy to work with, and no gum 

 is required in the actual process of mounting. 



The modus operandi is as follows : — Set the specimen in the 

 ordinary way by gumming on card. When set, remove from 

 the card, cleanse, dry, and place on a gelatine mount. Then 

 proceed to touch down the tarsi and antennae with the point of 

 a camel' s-hair brush dipped in warm water, and allow to dry for 



&c., could be " photographed." And thus, also, in another sense, the resem- 

 blance of the under sides of V. urticce and V. io to the dry twigs and dead 

 leaves of winter could be explained, while the supyression of colour 

 development in the under sides would account for the transference of 

 hrilliant colours to the upper sides and the reduction of the blacJc upper side 

 markings. F. io a.d antiop a which have the blackest under sides exhibit 

 the minimum amount of black in their lapper sides. 



