32 MANUAI, OF NATDRB STUDY. 



THIRD YEAR. 



A. — Plant Life. 



1. Lessons on Leaves. — a. Compare as to form, 

 margin, variation, surface. Take a number of 

 large leaves, as sycamore, maple, linden, catalpa, 

 iron weed, thistle, morning glory, pond lilies, ^ 

 beans, grass, etc. First classify on basis of general 

 outline, viz.: — Linear, lanceolate, wedge-sbaped, 

 spatulate, ovate, obovate, kidney-sbaped, orbicular, 

 elliptical. Keep repeating tbis exercise in several 

 lessons "until tbe cbildren are fairly well acquainted 

 witb tbe common forms. Let tbem find tbat tbe 

 forms lanceolate, kidney form, beart sbape and 

 ovate are widest near tbe base and taper toward 

 tbe apex ; and tbat tbe forms spatulate, wedge- 

 shape and obovate are widest near the apex and 

 taper toward tbe base, while the forms orbicular, 

 oblong, elliptical, linear and oval are widest at the 

 middle and taper equally toward apex and base. 

 Make drawings of leaves, showing tbe several 

 forms. As to margin compare the leaves of cherry, 

 peach, grape, apple, elm, beach, hickory, clover, 

 bean, violet, goldenrod, aster, oak, maple, etc. 

 Which of these leaves have entire edges? Which 

 serrate? Dentate? Crenate? Sinuate, etc? For 

 meaning of these terms, the teacher may consult 

 any good botany. 



