Extraction and Measurement Techniques 35 



blades damped to a block are perfectly satisfactory. For Avena straight 

 growth tests, guillotines such as those described by van der Weij 

 (1932), Yamaki (1948) or by Galston and Hand (1949) are very help- 

 ful. 



4. When guillotines are used, it is convenient to mount the 

 coleoptile cylinders on the teeth of fine hair combs (Schneider, 1938). 

 See figure 17. 



Fig. 17. An Anena straiglit-giowth test carried out on conil) teeth by the method of 



Schneider (1938). 



5. A fine ruler or a dissecting microscope with an ocular eyepiece 

 for measuring length of the sections. 



PROCEDURE FOR THE AVENA STRAIGHT-GROWTH TEST 

 Planting 



Place husked seeds of Victory oats in water in a suction flask and evacuate. 

 Soak for two hours, then discard the soak water. On glass plates covered with 



