230 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



lower parts of the islands than in the middle and upper regions. 

 The weather is often practically clear at sea level, while a few 

 hundred feet up it may be dark and gloomy, the clouds being 

 arrested as they strike the mountains and thus hanging as fog- 

 banks around the sides. Owing to the generally more open 

 arrangement of the vegetation, there is not the same intense 

 struggle among plants to get to the light that was noted in the 

 rain-forests of Cocos Island, some three hundred and fifty 

 miles northeast of the Galapagos. 



The most marked effect of light on vegetation is seen among 

 some of the species of the Cactaceae, which seldom grow in 

 shaded places, and, when they do so, are much stunted in 

 growth. Specimens of Plumbago scandens usually have a deep 

 red color when they grow in direct sunlight, a character that 

 is usually not developed on specimens in the shade. 



Winds 



The prevailing winds blow from the southeast, east-south- 

 east, and south-southeast, and are the regular trade winds of 

 this part of the Pacific Ocean. They blow quite regularly 

 from June until January, but during the remainder of the year 

 are very uncertain, and the waters surrounding the islands are 

 subject to long periods of calm. Our vessel had to depend 

 entirely on sail, and at one time it required from May 3rd until 

 June 23rd to go from Villamil, on the south side of Albemarle 

 Island, to Hood Island, a distance of about eighty-five miles. 

 We spent two weeks of this time anchored at Charles Island 

 waiting for wind, so that we were actually under way thirty- 

 six days. The calm was so complete at one time during this 

 trip that a flour tin, which was thrown overboard and which 

 happened to light right side up, was still in sight forty-eight 

 hours afterward. There are often light winds during the day 

 in the calm season, but they usually go down in the 

 evening, and unfortunately do not always come up again on 

 the following morning. It is very seldom that the winds come 

 from a northerly direction, and when they do they are usually 

 of short duration. Storms are very rare, but short squalls 

 sometimes occurred several times a day at Tagus Cove on 

 Albemarle Island during the months of March and April. 

 Wolf, in his paper on the Galapagos Islands, mentions similar 



