July, 1921 THE FLOCK BEHAVIOR OF THE COAST BUSH-TIT 127 
of value in connection with the general problem of group psychology. 
| LITERATURE CITED 
GRINNELL, J. 
1903. Call-notes of the bush-tit. Condor, vol. 5, pp. 85-87. 
Feerrr, J. P. 
1904. A preliminary study of the psychology of the English sparrow. Amer. 
Jour. Psych., vol. 15, pp. 313-346. 
1906. Further study of the English sparrow and other birds. Jbid., vol. 17, pp. 
248-271. 
SwWARTH, H. S. 
1914. The California forms of the genus Psaltriparus. Auk, vol. 31, pp. 499-526, 
ipl: 
TROTTER, W. 
1916. Instincts of the herd in peace and war. (London, T. Fisher Unwin, Ltd.), 
218 pp. 
Department of Zoology, University of California, June 11, 1921. 
GENERA AND SPECIES 
By RICHARD C. McGREGOR 
HAVE read with much interest and appreciation the article by Witiner 
Stone on the use and abuse of the genus. Briefly stated, Doctor Stone’s 
protest is against the excessive division of genera that has been proposed 
by some recent authors; he suggests that we use the broader generic divisions 
of a few years ago for nomenclatural purposes, restricting the finer superspect- 
fie divisions to occasions when such distinctions are required. This subject 
erupts more or less periodically’, and one might derive some entertainment 
from a study of its cycle and predict the year of the next activity. 
As ornithological nomenclature has been one of the chief sufferers from 
the abuse described by Doctor Stone, it would be appropriate for the Condor 
and other leading ornithological journals to publish comment on this subject. 
Therefore, a few words are offered for the sake of provoking discussion. 
The general tendency, in ornithology at least, 1s to recognize finer and 
more trivial characters and, accordingly, to break up old groups and to name 
more families, genera,.etc. With ever-increasing collections and the more 
intensive study of specimens, the systematist inevitably recognizes differences 
that escaped detection before, and exaggerates the significance of minor dif- 
ferences. The result is that the genus must be based upon slighter characters 
than formerly; the rank of the group is thus degraded. This may lead to a 
condition in which each species of a family is the representative of a genus. 
the interrelations of the species are no longer indicated, and the generic names 
become absolutely worthless. 
The groups of taxonomy are imaginary and have no existence in nature. 
1Science, vol. 51, 1920, p. 427. 
7For example, note the activity of about five years ago, indicated by Sumner, F. B., 
Science, vol. 41, 1915, p. 899; Van Name, W. G., Science, vol. 42, 1915, p. 187; Colton, H. S., 
tom, cit., Pp. 307; Allen, J. A., tom. cit., p. 492. ‘ 
