106 



margin were opposite. From the above it may be inferred that 

 if the position of these first, and by far the largest secondaries, 

 affected the condition of the base, as to its being opposite or not, 

 the greater number of leaves would not have had opposite bases, 

 but this in the leaves examined is not so. Hence it would appear 

 that the position of the first secondaries does not affect the base. 

 The secondaries arise at different angles in different leaves. 

 The largest angle found for the lowest secondaries was 74 





BASES OF SASSAFRAS LEAVES 





45 



65^ 



Ogf^ 



IQ.Sfo 



15.6f. 



Figure 7. 



degrees, the smallest 27 degrees. The usual angle is apparently 

 somewhere between 40 and 50 degrees. The other and smaller 

 secondaries likewise leave the midvein at various angles. These 

 are, however, as a rule much larger than the angles at which the 

 first two secondaries depart from the midvein. Sometimes the 

 angles of departure of the smaller secondaries are as large as 

 90 degrees. The largest angle measured was 93 degrees. 

 Another point in regard to the secondaries is that they are con- 



