124 NATURE STUDY REVIEW [9 lo— May, 1913 



A chart of some limited area, such as a street of the school 

 grounds, with the trees located and named furnishes another 

 means of getting the student familiar with forms out of doors. 



One of the writer's correspondents reports arousing con- 

 siderable interest in winter tree study by exhibiting in a store 

 window numbered twigs taken from trees grown in the streets 

 of the village and offering some simple prize for their identifica- 

 tion. Photographs of habits and barks might be added to such an 

 exhibit to advantage. 



In some of his classes the writer has assigned to each student 

 or allowed him to choose for himself an individual tree species to 

 be investigated and reported upon from the tree itself independ- 

 ently of text books. Such a scheme discovers the student with 

 powers of independent observation but it has been found neces- 

 sary to post a rather full set of questions to guide this elementary 

 research work. 



A tree book on a limited group or for a limited locality may 

 be gotten up by the more enthusiastic students embodying line 

 drawings or specimens and a short descriptive text for each spe- 

 cies represented. 



Keys may be devised for the familiar genera but work of 

 this kind cannot be expected of younger students. As an ex- 

 ample of a key such as has been suggested, there is appended one 

 made out for the Maples. 



Key to the Maples (Acer).* 



Leaf-scars opposite, narrow U or V-shaped ; bundle-scars conspicuous, 

 equidistant, typically 3, though sometimes each of these becomes com- 

 pounded ; fruit winged, in pairs. 



1. Conspicuous, narrow tooth present between leaf-scars, 2. 



1. Conspicuous tooth absent from between leaf-scars, 4. 



2. Buds white-downy, collateral buds generally present, twigs gen- 

 erally with a bloom. Box Elder (Acer Ncgundo). 



2. Buds smooth, collateral buds never present, twigs without bloom, 3. 



3. Buds with only one pair of scales visible, older branchlets white- 

 streaked, Striped Maple {Acer pennsylvanicum). 



3. Buds with several pairs of scales visible, branchlets not white- 

 streaked, Norway Maple (Acer platanoides) . 



4. Outer single pair of bud-scales equalling the bud in length, their 

 edges meeting and enclosing the bud, therefore generally only one pair 

 of scales visible; pith brown; shrubs or at the most small trees, 5. 



4. Outer pair of scales shorter than bud, their edges not meeting, 

 therefore several pairs of scales visible; trees, 6. 



5. Buds and twigs stout, smooth ; young bark with longitudinal white 

 lines. Striped Maple {Acer pennsylvanicum) . 



(*From Blakeslee & Jarvis's "Trees in Winter" with permission of the 

 Macmillan Company.) 



