MODE OF DI8SBCTIK6 EMS 



oved, and the insect by tbit ent will have becoi 



n hi, and Hi' « ill n"i then cbill the balsam. 



"To prepare A.phides foi on, liquids ma} be divid 



those used tor hardening the eemployed 'ring 



ime 1 lemng, don for several hours in weak 



alcohol will be of advantage. Thi alcohol must not b< 

 or tli«- albuminous portions \n i 11 bi ulated and becomi 



opaque. 



•• Weak acetic acid w ill render some portions tough, and the same 

 action is also well effected by ;i weak solution of phosphoric <>r of 

 nitric acid. 



"The action <>f ordinary ether upon Aphides is not well under- 

 stood. Their bodies are speedily destroyed by plunging them into the 

 liquid. At the same time :i considerable stream of air-bubbles con- 

 tained in the tracheae is expelled, and of such a volume as would lead 

 in tiic supposition that much of this air musl be in some stal 

 solution in the body-juii 



" The reaction of weak potash has beeu before noted. Asa rule, 



the germinal matter resists its union for a considerable time. 



Simultaneously this reagent usually stains it a bright gamboge yel- 



I ii some genera notably Lachnusand 1 >ryobius potash 'i< epens 



kedly the violet dye natural i<> these Aphides. In other 



I have found potash to evoke the violi from spe< imens 



mil. i This <lvc i- fugitive, and if discharged by an 



cannot !"■ again n I bj the action of an alkali. S 



:uul ammon >i i 1 1 lt out thi< color. 



•• Advantage m:n be taki n of the fact that tb< rder 



in which the tissues resist the intrusion of a foreign 

 dye. Thus the germinal and most vitally eudowi 

 dying by carmine, logwood, and such coal-coloi 

 the portions in process of exfoliation and decay absorb ii the 

 mosl readily For such purposes, weak alcohol may be i 

 slightly alkaline bj ammonia, and tinged with a little carmii 

 cochineal solution. Dilute chromic acid both tinges the ii 

 \illow and renders them tough. Solutions of osmic acid also may 

 be used to advantage, and, in short, the usual reagents employ < »1 for 

 conducting minute anatomy may be taken with due circumspection 

 and tenderm 



•• For labelling specimens, paste will be found much more adh< 

 than gum The former u\-.\\ be preserved for some in a 



well-closed bottle, if a little aqueous solution of ublimate 



Lirred into it." ("Monog. British Aphid* 



