Stewart — Botanical Conditions on the Galapagos Islands. 277 



mountains on the island which vary in height from 3,150 to prob- 

 ably over 5,000 ft., and several mountains of lower altitude. All 

 of the larger mountains are extinct volcanoes each of which has 

 an immense crater at its top. These craters are all inactive at 

 the present time except the one northwest of Villamil, on the 

 south side of the island, Sulphur fumes and other vapors issue 

 from the floor of this crater at times, and there are also two small 

 active sulphur volcanoes in it, each of which is surrounded by a 

 large quantity of almost pure sulphur. There has been some 

 volcanic activity at Banks Bay during the last few years, from 

 small craters* on the west side of the mountain. With these ex- 

 ceptions there has probably been no volcanic activity of the is- 

 land for a great many years. There are many low hills on vari- 

 ous parts of the island, some of which are small craters or blow- 

 holes, and others simply masses of volcanic debris. 



Banks Bay. 



Banks bay is a broad, open roadstead on the west side of the 

 island, near its northern extremity. The main mountain at this 

 place is a broad flattopped crater with steep sides, which prob- 

 ably rises to a height of over 5,000 ft. There is still a smaller 

 mountain close to the north shore of the bay that has an eleva- 

 tion of 2,360 ft. according to the chart issued by the Hydrogra- 

 phic Office. There are also a number of smaller craters and 

 hills around the base of the main mountain, and along it sides, 

 which usually have an average height of less than 100 ft. The 

 base of the main mountain is separated from the shore by a 

 broad plain which is covered with beds of comparatively recent 

 lava on which there is very little vegetation. There are places, 

 however, on this plain which were not covered by the more re- 

 cent flows of lava, on which there is a considerable amount of 

 xerophytic vegetation. 



Unfortunately this region was not explored botanically, so 

 that all of the information concerning its flora is due to the kind- 

 ness of other members of the expedition who visited this place. 

 At least three botanical regions are represented here, viz.: the 

 dry, transition, and moist regions, and possibly a fourth, as the 

 vegetation around the top of the mountain appeared from a dis- 

 tance to be quite different from that lower down. With the ex- 

 ception of the transition, no estimate was made concerning the 

 extent in elevation of these regions. 



