1920 j Recent Literature. 163 



may be available to students of the Galapagos avifauna, leaving the critical 

 study of the 5,916 specimens of land birds and the collection of nests, eggs 

 and stomach contents for future investigation. 



While it is regrettable that the entire collection could not have been 

 worked up promptly by Mr. Gifford, who of course knows more about it 

 than anyone else, we are nevertheless grateful for the large amount of 

 interesting information relating to the life histories of the birds of these 

 famous islands, which he has made available to the student. 



Of the thirty-six species referred to in the paper all but three are resident 

 forms. The Barn Swallow, was found at Cocos Island on September 2 and 5 

 and at Charles Island on October 11 and 12, and a Bobolink came onboard 

 the vessel in lat. 7° 23' N. long., 97° 48' W. on September 28 and again in 

 lat. 14° 24' N. long., 106° 42 ' W. on October 3, these locations were between 

 300 and 500 miles off the Central American coast. A Redstart also came 

 on board near the last mentioned station. These records will prove of 

 interest to students of migration. — - W. S. 



Hall and Grinnell on Life-Zone Indicators in California. 1 — This 



important and timely paper should be read by all students of geographical 

 distribution. As the authors point out it is only the naturalist of wide 

 experience and with a knowledge of both zo'ilogy and botany who can 

 accurately judge of the zonal affinities of a given region, and as the attempt 

 is too frequently made by those who are not so qualified, grievous errors are 

 made and authors often, from lack of knowledge of the situation which 

 confronts them, fall back upon the unfortunate and reprehensible practice 

 of coining special terms of their own to fit the apparently anom dous condi- 

 tions which they find. The present authors have presented a list of plants 

 and vertebrate animals which are characteristic of the several life zones 

 that occur in California, as a guide for those who are studying zonal distri- 

 bution of life in that State. They also offer a list of influences which tend to 

 interfere with the orderly succession of life zones as they would occur if 

 dependent wholly upon temperature and altitude. Foremost among 

 these is of course, slope exposure, followed by air currents, cold water 

 streams, evaporation from moist soil, proximity to large bodies of water, 

 influence of lingering snow banks, changes in vegetable covering, extent 

 of mountain area, and rock surfaces. Many of these affect plant life only, 

 though a knowledge of them may also explain many local anomalies in the 

 distribution of animals. 



The trouble heretofore seems to have been that botanists rely too much 

 upon soil composition and character to account for distribution, while 

 zoologists — some at least — have ignored everything but temperature 

 and altitude. The happy combination of a botanist and zojlogist in the 



1 Life-Zone Indicators in California. By Harvey Monroe Hall and Joseph Grinnell. 

 Proc. Calif. Acad. Sciences. Fourth Series. Vol. IX, No. 2, pp. 37-67. June 16, 1919. 



