Vor. I] STEWART—BOTANY OF THE GALAPAGOS ISLANDS Doh 
TABLE OF GALAPAGOS TEMPERATURES, 1905-1906—Continued 
Morning Noon Evening 
Station Date FMGE SRE SUT Gaeta ae 
Water Air Water Air Water | Air 
Tower Isl. Sept. 14 73 71 
Sept. 15 | 71 68 73 74 73 70.5 
Bindloe Isl. Sept. 16 12508 bre 
Sept. 17 | 72 69 (Panola sir. 
Sept. 18 | 71 69 
Abingdon Isl. Sept. 18 73 72 
Sept. 19 | 71 70 73 72 
Sept. 20 | 72 68 72 70 
Sept. 21 | 70 69 72 70 
Sept. 22 | 70 70 72 69 
Wenman Isl. Sept. 24 76 74 
Twelve miles west of 
Wenman Isl. Sept. 24 76 73 
Culpepper Isl. Sept. 25 76 74.5 
From this table it is seen that the warmest weather of the 
year occurs in the months of February and March, and the 
coldest during the months of July, August, and September. 
There is no great amount of difference in the temperature of 
the air morning and noon, 5° F. being about the average, 
while the difference in the temperature of the water is even 
less than this. The air is usually 1° to 3° warmer than the 
water in the morning, except during the spring months, when 
the opposite is the case. 
The uniformly low temperature for an equatorial region is 
due to the coolness of the water which surrounds all but the 
northernmost islands of the group. The Humboldt current, 
which sweeps up from the antarctic regions along the west 
coast of South America, turns outward at about the latitude 
of these islands and bathes their shores with unusually cool 
water for several months of the year. The water remains 
cool until the sun reaches well south of the equator, in the 
autumn and winter months, when it begins to become warmer 
until it reaches its highest temperature in February and March. 
After the sun passes the equator on its way north, the water 
rapidly becomes cooler, the colder water seeming about to keep 
