CHAPTER XIV 

 THE PREPARATION OF SECTIONS 



The preparation of thin sections of plant tissues is an abso- 

 lute necessity in the study of plant histology, not only that cell 

 structure may be clearly seen but that the association of cells 

 into tissues and the mutual relationship of the different tissue 

 systems may be brought to light. Whether sections can be 

 cut forthwith without special preparation of the subject to be 

 sectioned depends upon the nature of the material and the partic- 

 ular question regarding it that is to be solved. The method 

 of procedure to fit different cases will now be given. 



Cutting Sections Free-hand. — Good histological work 

 can be done with some materials, such as the mature parts of 



Fig. 138. — Manner of holding the razor and object in cutting sections free-hand. 



stems, roots, and leaves, by holding them between the thumb 

 and forefinger of one hand while the section razor is wielded 

 by the other (see Fig. 138). The forefinger is held hori- 

 zontal and the razor rests upon it, being pushed from point to 

 heel in cutting the section. There is never danger of cutting 

 too thin sections by this method; rather, most of the sections 

 are too thick, and skill comes only with much practice. Sup- 

 pose a cross-section of a stem is being cut, it is not necessary 

 that the section be complete, and the small but thin bits which 

 one is sure to get in his efforts to secure thin sections are the 

 most satisfactory under high powers. A very small segment 



251 



