2498 



Journal of Applied Microscopy 



Sectioning of Wheat Kernels. 



During some investigations being made by this bureau upon the chemical 

 and structural characteristics of certain wheats, it became desirable to make 

 sections of the whole grain, but the hardness of the kernels made it necessary to 

 modify the ordinary methods of embedding. The method finally adopted con- 

 sisted of softening with glycerine and then embedding in paraffin. 



After making several sets of experiments to determine the effect upon the 

 grains of various percentages of water and alcohol, and of water and glycerine, it 

 was found that not more than from 5 to 10 per cent, of water should be present. 



Fig. 1. — Photo-micrograph of cross section of wheat kernel. 



In detail the method is as follows : The grains are first soaked in 90 to 95 

 per cent, alcohol for several days (10 to 14), after which 90 per cent, glycerine 

 is added to the alcohol in small portions at intervals of a few days until the pro- 

 portions of alcohol and glycerine are about equal. The material is then allowed 

 to stand until the grains have attained a firm, cheesy consistency. This time 

 will vary with the nature of the grains from three weeks to as many months. A 

 larger per cent, of water will hasten the process, but the grains will be swollen 

 by it. When the softening has been completed, a layer of the material is exposed 

 to the air in a shallow dish with a sufficient quantity of the liquid to cover it. In 

 two or three days the alcohol will have evaporated, thus leaving the grains 

 infiltrated with the glycerine and a very little water. To embed, the following 



