252 
down from the table-land. The canyon opened suddenly into 
the valley of San Juan River. At this place the river valley is 
bordered on both sides by almost perpendicular walls of, I judge, 
about 300 feet. These high walls or bluffs give the name to the 
town of Bluffs. On the north side at short distances between, 
shorter or longer box canyons run from the San Juan Valley into 
the table-land. One of these box canyons is illustrated (fig 
Fic. 42. Box canyon in the bluffs north of San Juan River, with alcoves. 
42). ‘The canyons and their branches often end in alcove-like 
cavities with over-hanging rocks. nder these rocks are usually 
found a species of Mimulus growing in the crevices, sometimes 
even under the ceiling of the alcove. After blooming the plant 
sends out runners like the strawberry, but these runners grow 
in all directions, up or down or horizontally. Wherever they 
happens to take place in the ceiling, the new plant formed at 
the place will grow with the root up and the flower down. In 
the crevices and in the loose soil and gravel under this Mimulus, 
I often found growing Aquilegia micrantha, a Primula, a Lim- 
