ILLUSTRATIONS. 



Page 



Fig. 1. The Light-house at Rock Harbor, Isle Royale 16 



2. Cliffs between Tonkin and Conglomerate Bays 16 



3. Summer, storm waves upon the beach (I. 1) at the head of Tonkin Bay, 16 

 south of the Light-house 



4. Sand beach at the head of Conglomerate Bay (I, 1) 16 



5. Beach pool (I, 1) near Tonkin Bay 16 



6. Transition from the beach (I, 1) to rock clearing (I, 2), south of the Light- 

 house 16 



7. Natural rock opening (I, 2) or avenue, farther up the slope than in Fig. 6. 16 



8. Natural rock clearing or opening (I, 2) north of the Light-house at Rock 

 Harbor 16 



9. Natural rock clearing (I, 2) south of the Light-house 16 



10. Arbor Vitae bog (I, 4) near Tonkin Bay 16 



11. View from the Jack Pine ridge (I, 5), looking toward the head of Con- 

 glomerate Bay 16 



12. Second growth of White Birch on the Trail to the Jack Pine Ridge (I, 5), 

 Conglomerate Bay 16 



13. Jack Pine ridge (I, 5) Conglomerate Bay 16 



14. Sphagnum-Black Spruce bog (I, 6) near the Jack Pine ridge 16 



15. Small island near the head of Rock Harbor (HI, 1) 16 



16. Bulrush zone and delta at the head of Rock Harbor (III, 3) 16 



17. Exposed section of spit formed as the water level has lowered in Rock Har- 

 bor, near the beginning of the trail to Sumner Lake (III, 4) 16 



18. Sumner Lake (III, 5) 16 



19. Western end of Sumner Lake (III, 5) 16 



20. Northeastern margin of Sumner Lake (III, 5) 16 



21. Southeastern corner of Sumner Lake (III, 5) 16 



22. Western end of Sumner Lake (III, 5) 16 



23. Northern shore of Sumner Lake (III, 5) 16 



24. Rock opening about Camp on Siskowit Bay (V, 3) 16 



25. Rock opening at the Siskowit camp (V, 3) 16 



26. Rock opening on Siskowit Bay (V, 3) 16 



27. Border of the opening about the Siskowit Camp (V, 3), near the beginning 



of the trail to Siskowit Lake (V, 4) 16 



28. Ant nest in the opening at the Siskowit Camp (V, 3) 16 



29. General character of the south shore, near the eastern entrance to Siskowit 



Bay (V, 2) 16 



30. Rock pool on the beach (V, 2), where a variety of invertebrates was 

 secured 16 



31. Saxifraga aizoon on beach (V, 2) .- 16 



32. General view along the shore at V, 2 16 



33. Farther up the same slope as Fig. 32 and adjacent to it 16 



34. Still farther up the slope and adjacent to Fig. 33 16 



35. Looking up the slope on the western portion of Station V, 2 16 



36. Upper portion of western part of Station V, 2 16 



37. De'tail of western part of Station V, 2. .•. 16 



38. Character of ground cover in parts of the Balsam-Spruce forest (V, 4) 16 



39. Open space in the Balsam-Birch forest (V, 4) 16 



40. Open space in the Balsam-Birch forest (V, 4) 16 



41. Tamarack Swamp (V, 5) 16 



42. Spruce margin of Station V, 5 16 



43. Black Spruce margin of Station V, 5 16 



