DISSECTING INSTRUMENTS. 343 



CHAPTER XIII. 



ON THE DISSECTION AND PKEPARATION OF VEGETABLE 

 AND ANIMAL STRUCTURES. 



By far the greater number of the wonderful and highly 

 interesting structures which it may fall to the lot of the 

 microscopist to examine, are not presented to him in a simple 

 and isolated form, but are more or less combined with other 

 tissues from which they require to be extracted or separated 

 by a process termed dissection ; this may be divided into two 

 branches, one in which the subject is large and all its parts 

 perfectly tangible and visible to the unassisted eye, whilst in 

 the other the aid of the microscope and of very dehcate 

 instruments is requisite for its due performance, the first is 

 called coarse or rough, the second minute anatomy; in both, 

 certain cutting and other implements are necessary, which here 

 demand our attention. 



Dissecting Forceps. — In addition to the forceps already 

 described at page 135, two or three other kinds will be 

 required for the purposes of dissection; of these the most 

 useful are represented at A in fig. 227 ; they should be com- 

 posed entirely of steel, and be at least five inches in length. 

 They may be denominated the straight and the curved ; of the 

 first kind, or that shown at A, two pairs will be requisite, one 

 having the extremities broad, and the other sharp pointed ; if 

 large dissections be undertaken, a stiU stronger pair, with the 

 extremities broad, and made rough like a file, will also be 

 necessary. In dissecting under the microscope, the curved 

 pointed pair shown at F will be found most convenient. In 

 all these instruments the points should fit accurately together, 

 sometimes those that are very sharp are apt to cross, this may 

 in a great measure be prevented by having the branches wide 

 at the Ijase where they are rivetted. The points may be 



