APHIDES IN AMBER. 163 



The Rev. F. W. Hope, many years ago, dissolved 

 some of his specimens and successfully extricated the 

 entombed insects ; but this must be a hazardous pro- 

 cess, for amber is singularly indifferent to the action 

 of most solvents.* Besides all this, insects in amber 

 have been sufficiently prized to make attempts of their 

 imitation remunerative, by slitting portions and again 

 uniting them by a dense varnish after the surreptitious 

 introduction of certain objects. 



When amber specimens are too valuable to cut up, 

 much information may be gained optically by tempo- 

 rarily cementing with Canada balsam small discs of 

 thin microscopic glass, or even mica, over the specimens 

 to be viewed. Sometimes a similar disc on the opposite 

 side will be necessary ; care being taken to keep the sur- 

 faces of both these discs parallel, otherwise the trans- 

 mitted light will not come direct to the eye. The 

 objective of the microscope will then penetrate far 

 into the amber mass, and bring out details quite in- 

 visible without such a treatment. 



At other times the whole specimen may be merged 

 in a glass trough containing castor-oil, or some liquid 

 of high refractive power, that does not act on the amber 

 itself. After examination the specimen can be easily 

 cleaned by using spirits of turpentine, which does not 

 act on the amber. 



The earliest notices that I have met with as to 

 Aphides in amber are by Dr. G. Carl Berendt, who, at 

 various periods from 1830 up to the appearance of his 

 great work in 1845, published papers on the fossil insects 

 of the ancient world. f Amongst these earlier memoirs 

 I find notices of seventeen specimens of Aphides of the 

 genera comprising Aphis, Lachnus, and Schizoneura. 

 Unfortunately, they are not figured, and it is not possible 

 to compare other like specimens except by means of 

 the identical ambers referred to. 



* F. W. Hope, " On Succinic Insects," ' Trans. Ent. Soc.,' Lond., 

 iii, pp. 133 to 147. 

 f G. 0. Berendt, ' Ein Beitrag zur Thiergeschichte der Vorwelt.' 



