"Mbcw tbe M00&6 are Xeaf*grcen 65 



to the margin, as in the calla lily and the pickerel 

 reed. The other fashion shows no mid-rib, and the 

 veins all run from stem to tip, as in the corn, grasses, 

 lily-of-the valley, and others. 



Some net-veined leaves apjDear at first glance to be 

 parallel- veined ; a little examination will show the 

 difference. 



Plants which have two seed-leaves, or cotjdedons, 

 have woody or not hollow stems, and the leaves have 

 radiated or net veins. Reaching the beginning of 

 the blade, the woody fibre in the stem divides into a 

 main central line and various branches. . These veins 

 are not only a frame-work, but as they are hollow 

 they serve as canals or a circulating system to carry 

 the sap into all parts of the leaf and return it to the 

 stem, to visit all other parts of the plant. 



The form of the leaf in even minute particulars 

 depends upon the carrying out of woody fibre. 

 Whenever it ceases or gives way the parenchj^ma or 

 pulp and the covering skin also give way. In this 

 manner the great variety of form in leafage is pro- 

 duced. 



All parallel-veined leaves have smooth, even edges. 

 Some net-veined leaves, as those of the senna, the 

 buckberry and American indigo, have also even 

 edges. Most net- veined leaves have cut or uneven 

 margins. 

 5 



