34 



THE LEAF 



VEINING 



Material. — A specimen of each of the different kinds of veining. 

 For parallel veining any kind of arum, lily, or grass will do ; for net 

 veining, ivy, maple, elm, or peach, etc. Classes in cities can use leaves 

 from potted plants of wandering Jew {^Zebrina pendula), calla lily, and 

 other easily cultivated specimens, or blades of grass, plantain, and vari- 

 ous parallel and net veined weeds can be picked up here and there, 

 even in the largest cities. Have a number of leaves placed with their 

 cut ends in red ink from three to six hours before the lesson begins. 



37. Parallel and Net Veining. — Com- 

 pare a leaf of the wandering Jew, garden 

 lily, or any kind of grass, with one of cot- 

 ton, maple, ivy, etc. Hold each up to 

 the light, and note carefully the veins or 

 little threads of woody substance that 

 run through it. Make a drawing of 

 each so as to show plainly the direction 

 and manner of veining. Write under 

 the first. Parallel veined, and under the 

 second, Net veined. This distinction of 

 leaves into parallel and net veined cor- 

 responds with another important differ- 

 ence in plants, existing in the seed, and is used by botanists 

 in distinguishing the two great 

 classes into which seed-bearing 

 plants are divided. 



54. — Paral lel-veined 

 leaf of lily of the valley 

 {after Gray). 



38. Pinnate and Palmate Vein- 

 ing. — Next, compare a leaf of 

 the canna, or of any of our 

 common garden arums, with one 

 of the elm, peach, cherry, etc., 

 or with a leaflet of the rose or 

 clover. Hold both up to the light and observe carefully 

 the veins and reticulations. What resemblance do you 

 notice between the two.? What difference.? Which is 

 parallel veined and which is net veined .' Make a drawing 

 of each, and compare with the first two. Notice that 



55. — Palraately net-veined leaf of 

 Asarum europ(Bum.. 



