RECENT LITERATURE 
245 
Fallow deer {Dama dama) May 3 
Sambar {Rusa unicolor) June 18 
Hog-deer (Hyelaphus porcinus) .July 8 
It would be interesting to have dates from other zoological gardens, both in 
America and Europe, for comparison. 
— N , Hollister, 
RECENT LITERATURE 
Hall, Harvey Monroe, and Joseph Grinnell, Life-Zone Indicators in Cali- 
fornia. Proc. California Acad. Sci., ser. 4, vol. 9, no. 2, pp. 37-67. June 16, 1919. 
Few devices for handling the data of geographic distribution of animals or 
plants have been more useful than the life-zone. For satisfactory zonal diag- 
nosis of a given locality it has usually been necessary to make an exhaustive 
study of the entire fauna and flora. To obviate this necessity, so far as California 
is concerned, is the hope of the authors of this paper, who proceed to list certain 
critical species of plants, amphibians, reptiles, birds, and mammals as life-zone 
indicators. 
Almost at the outset the importance of recognizing local modifying factors is 
emphasized. Those considered are slope exposure, air currents, streams carry- 
ing cold water, evaporation from moist soil, proximity to large bodies of water, 
influence of lingering snow banks and of glaciers, changes in vegetal covering, 
extent of a mountain area, rock surfaces, miscellaneous local influences. 
Five criteria are given as among those used in the selection of the life-zone 
indicators. Briefly stated these are (1) Only breeding records have been taken 
into account. (2) In plants perennials are usually preferred to annuals. (3) The 
more abundant a species the greater its value as an indicator. (4) A particular 
indicator, though constant in zonal position in one portion of its range may be 
unreliable when its entire range is considered, due ‘‘perhaps to the possible 
development of hardy strains in one portion of the range and not in another,” or 
to some other cause. Furthermore, bio types, similar in external characters but 
reacting differently to their environment, may escape detection by the taxono- 
mist. (5) So far as possible, indicators listed by C. Hart Merriam are used, 
since the authors in the main accept his delimitation of the life-zones. 
The lists of mammalian indicators include: For the Lower Sonoran, 78 forms 
belonging to 34 genera; Upper Sonoran, 48 forms, 18 genera; Transition, 27 forms, 
14 genera; Canadian, 30 forms, 15 genera; Hudsonian, 7 forms, 5 genera. No 
mammals, reptiles or amphibians are listed for the Alpine Arctic, the sole indi- 
cator aside from plants being the rosy finch, Leucosticte tephrocotis dawsoni. It 
so happens that among the animals listed there are more mammalian indicators 
than bird, reptile, or amphibian for each zone except the Transition (which has 
three more bird indicators than mammalian) and the Alpine Arctic. 
The paper will be of interest to every student of the distribution of the higher 
vertebrates of the western states. 
— Walter P. Taylor. 
JOUENAL OF MAMMALOGY, VOL. I, NO. 5 
