CHAPTER VIII. 

 SECTION-CUTTING. 



IN the preceding chapter the necessity of dissection has 

 been shown, in order to gain an insight into the economy 

 of things. It is none the less important, however, to be 

 able to cut a thin slice of any given object in order to show 

 the details in situ. 



We should be very careful not to form hasty opinions, 

 from the observation of sections alone, as vessels will 

 appear of different shapes according to the plane in which 

 they have been cut. Circular vessels cut through obliquely 

 give an oval outline ; but in the direction of their length, 

 squares. 



Section-cutting may conveniently be divided into three 

 methods : 



1. Without the use of the microtome (section-cutter), and 

 even before hardening or otherwise preparing the subject. 



2. With the microtome, such subjects as the stems of 

 plants, leaves, animal preparations, and the like. 



3. The cutting of hard substances, coal, rock, bone, and 

 subjects of this nature. 



To proceed with the first method, we find some workers 

 cutting slices on or between pieces of cork without the use 

 of any appliance whatever save a knife or razor. Others 

 use even more primitive methods, and perhaps by long 

 continued practice may arrive at fair results, though the 

 author has never seen uniformly thin and good specimens 

 cut by the hand alone. 



Some when examining animal tissues, " prefer to snip off 



