132 STUDY OF COMMON PLANTS. 



XIII. THE PINE FAMILY. CONIFERS. 



MATERIAL REQUIRED. 



Twigs of the following species: White pine, Pinus Strobus, L. ; Aus- 

 trian pine, Pinus A ustriaca, Hoess ; Norway spruce, Plcea exceka, 

 Lk. ; Hemlock, Tsuga Canadensis, Carr. ; Juniper, Juniperus corn- 

 munis, L. ; Red cedar, Juniperus Virginiana, L. ; Arbor Vitae, 

 Thuja occidentalis, L. 



Mature fruits of the preceding, and flowers, both staminate and pis- 

 tillate, as far as these can be procured. 



Substitutions, such as Scotch in place of Austrian pine, may be made 

 as occasion requires. 



"WHITE AND AUSTRIAN PINE. 



I. Compare branches of the two species as to surface 

 markings and other external characters. 



II. Compare the foliage leaves. 



1. How many are produced in a fascicle? Examine 



specimens enough of both species to determine the 

 general rule, since exceptions frequently occur. 



2. How do those of the two species differ in length, 



thickness, rigidity, and color ? 



3. With a sharp knife make a transverse section of a 



leaf of each kind. Examine with a lens and note 

 difference of outline. 



III. Examine next the different sorts of scale-like leaves. 

 Notice 



1. Differences of size and texture. 



