332 DIRECTIONS FOB THE MICROSCOPE. 



up, and thus rendering visible, the smallest vessels which could be dis- 

 covered by the microscope, to trace their courses and communications, 

 or sometimes to inject them with coloured liquors. 



PARTS OF INSECTS FOR THE MICROSCOPE. 



The head and the parts of the mouth can seldom be examined without 

 the aid of a microscope ; consequently, nmch still remains to be done 

 in this department of science : the palpi, mandibles, maxillce, Sjc (tor 

 their use and situation, see page 21 to 29) would form a most beauti- 

 ful series of objects, which may be rendered still more interesting by 

 a knowledge of the manners, economy, &c. of the animals; these parts 

 can always be separated and displayed, however old the specimen may 

 be, by being plunged into boiling water, and then placed on a piece of 

 blotting paper to extract whatever water remains about them : the 

 parts of the mouth m.ay then be displayed by means of the setting 

 needle, and when the articulations are tine and in danger ol' breaking, 

 a camel's hair pencil will be found extremely useful. The abdomen 

 and legs frequently display the most lively and brilliant colours, espe- 

 cially the C/irysalid/£ ; the minute Ichneumons are no less to be admired, 

 either for their beauty or the singularity of their manners. The wings, 

 for transparent objects, form an endless variety; the disposition of the 

 nerves is frequently found essential in their generic character, as in the 

 Tcnthredinida: these, no doubt, would frequently, with other parts, be 

 useful in forming natural genera of many families, both of Hyme- 

 noplera and Diptera, as the parts are easy of examination : in fact, there 

 is no part of an insect but what may be rendered a pleasing and in- 

 teresting subject. The copious directions for collecting them that I 

 have before given, will render any further directions on tliis head un- 

 necessary. 



There is no substance in nature but what will bear an examination 

 by the microscope: consequently this instrument is a never-failing 

 source of rational amusement; the hair of animals, the feathers of 

 birds, the scales of fish, bones, the circulation of the blood, cuttings of 

 wood, seeds, vegetable infusions, the leaves of plants, and the innu- 

 merable unimaicula which are found in every decaying substance, will 

 aiford employment never to be regretted : 1 shall therefore close this 

 part of the subject by a few brief directions for preparing, examining, 

 and obtaining the above, which I trust will be found sufficient for the 

 purpose. 



