EXPLANATION OF THE PLATES. 



Plate DXLVI. Pintjs flexilis. 



1. A branch with staminate flowers, natural size. 



2. A staminate flower, enlarged. 



3. Diagram of the involucre of the staminate flower. 



4. An anther, side view, enlarged. 



5. An end of a branch with pistillate flowers, natural size. 



6. A pistillate flower, enlarged. 



7. A scale of a pistillate flower, upper side, with its ovules, enlarged. 



8. A fruiting branch, natural size. 



9. A cone-scale, upper side, with its seeds, natural size. 



10. A cone-scale, lower side, enlarged. 



11. Vertical section of a seed, enlarged. 



12. An embryo, enlarged. 



13. Tip of a leaf, enlarged. 



14. Cross section of a leaf, magnified fifteen diameters. 



15. Winter branch-buds, natural size. 



Plate DXLVII. Pintjs flexilis. (From northern Arizona.) 



1. A branch with young cones, natural size. 



2. A cone, natural size. 



3. A cone, natural size. 



4. Tip of a leaf, enlarged. 



