I/O PRACTICAL MICROSCOPY. 



forceps, as well as a pair of the straight variety, with fine 

 points, are necessary. 



A bull's-eye condenser for concentrating light upon the 

 object, and a small glass syringe for washing subjects and 

 removing or adding to the liquid contents of the trough, 

 complete the dissector's outfit. 



And now having his apparatus ready, the student will 

 naturally be looking about for something to dissect. He 

 need not seek long at any season of the year, but in the 



FlG - 



event of his not being able to fix on what he shall com- 

 mence with, the blow-fly, Musca vomitoria, is suggested. 



Plenty of work will be found in the blow-fly if it be done 

 properly, and after this the student may take in hand 

 the water-beetle, Dytiscus marginalis ; the grasshopper, 

 Locus fa mridissima ; or the common house cricket, Acheta 

 domestica. 



In the above, the student will find the tongues, antennae, 

 eyes, wings, legs, segments, spiracles, and tracheae, an 

 interesting study, and besides these organs, gizzards will 

 be found in the last three. 



rftie insect (if not too large) should first be held in the 

 stage forceps as shown in Fig. 66, or in any other con- 

 venient manner, and examined with a low power (say a 

 2-inch objective), to show its general character, and give an 

 insight into the manner in which the appendages should be 

 dealt with. 



The proboscis of the fly may be obtained by pressing 

 the thorax, so as to cause protrusion, placing the organ 



