38 REVIEWS AND BOOK NOTICES. 
‘t The normal inherent ae in size, of the whole bird and 
its members, is at least twelve per c ene ae the mean. (This is 
independent of all p a circumstances. )” 
. “ Size varies in direct ratio with the latitude of the breeding 
season. 
‘* Size of peripheral parts, as compared with total size, varies in 
inverse ratio with the latitude of the breeding-place. (Cf. Allen, 
Bull. Mus. Comp. Zool. I, p. 229).” 
Intensity of coloration varies in direct ratio with the tempera- 
ture and humidity of the pheno 8 fe Moisture, however, 
intensifies color more than heat; aridity tones down color more 
than cold. Birds from hot dry aa ie therefore, are paler, ceteris 
paribus, than birds pen wet places of the same or even lower 
temperature. (Cf. Allen, op. cit., p. 239).” 
“ Variation, unconnected with age, sex or season, is in inverse 
ratio with the migration or changeable geographical distribution 
of individuals.” 
Other propositions are announced relating to variations depend- 
ent upon age and sex in the group especially under consideration. 
They all appear to have been strictly followed, and the conclusions 
thus reached seem to be in the main thoroughly tenable. The 
propositions relating to geographical variatign, though as yet far 
from being generally accepted, we are convinced are well founded, 
as the more thoroughly they are tested the more fully are they con- 
firmed.— J. A. A. 
MONOGRAPH OF THE SpHENISCcID&.*—In this important memoir 
of forty-two pages we have one of the most valuable contributions 
to the literature of the Spheniscide that has yet appeared. It 
opens with a critical historical synopsis of all preceding papers 
treating of the group, from Linnzus down to the present year, in 
~ onymy and the gradual accumulation of our present knowledge 
the family. From the two species known in 1766 to Linneeus, 
the number had increased in 1781 to eight valid species, four of 
te which were then made known for the first time by Forster in his 
_ valuable history of the group. The next valid new species was de- 
_ scribed by Brandt in 1837, “the first for half a century.” Later 
the he of valid species was increased to twelve, the number 
a recognized by Schlegel in 1867, and by our present author. 
a observes ; “ As far as the determination of the species is concerned, 
m e EA wia 8 woodcuts. coopt 
eee ee S ee ee S eee 
a which are briefly yet lucidly traced the principal changes of syn- 
2 Respecting Schlevel’s judicious revision of the group Dr. Coues - 
ORE S ie & Melina ce vid the Spheniscide. By Dr. sd Soi eit Proc: 
