EXPLANATION OF THE PLATES. 



Plate DXXXVIIL Pinus Strobus. 



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 anther, front view, enlarged. 



6. A branch with young cone and pistillate flowers, natural size. 



7. A pistillate flower, enlarged. 



8 and 9. Scales of a pistillate flower, lower side, with their bracts, enlarged. 



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



11. Tip of a leaf, enlarged. 



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



13. A cluster of young leaves with its sheath. 



Plate DXXXIX. Pinus Strobus. 



1. An autumn branch with young cones, natural size. 



2. A fruiting branch, natural size. 



3. A cone-scale, lower side, natural size. 



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



5. A seed, enlarged. 



6. A seed with its wing, natural size. 



7. Vertical section of a seed, enlarged. 



8. An embryo, enlarged. 



9. A cluster of leaves, natural size. 



10. A cluster of winter branch-buds, natural size. 



11. A seedling plant, natural size. 



