THE ELEMENTS OF VEGETABLE 

 HISTOLOGY 



CHAPTER I 

 PREPARATION OF SPECIMENS 



THE preliminary operations in the preparation of 

 plant tissues for micro-examination include sectioning 

 and powdering of the material under consideration. 

 Either or both of these procedures may be necessary 

 because plant organs are usually too large and too thick 

 for direct examination. Although much information 

 may be gained from a surface examination by the use of 

 reflected light, it must be remembered that details of 

 inner structure are of the greatest importance in vege- 

 table histology and a knowledge of these details can 

 only be gained through examination of powdered or 

 sectioned materials. 



SECTIONING METHODS 



The methods employed in the preparation of sec- 

 tions or tfyin slices of plant parts vary according to the 

 texture of the tissues and the type of section required. 

 In general, the methods may be divided into (a) those 

 in which infiltration, or the permeation of the cell with 

 a supporting medium, is necessary and (6) those in 



