284 
mixo-chimeras, and that it may be 
possible to obtain them in pure races 
as Burgeff has done in Phycomyces 
through the germination of the zygo- 
spores. 
The individual mutants considered 
in the present paper are representative 
The Journal of Heredity 
of many variant forms that have arisen 
by mutation in the nonsexually propa- 
gated races of Mucor genevensis. They 
add to the evidence, already obtained 
from other groups, that mutations are 
not restricted to processes involved in 
sexual reproduction. 
HISTORY OF “X” MUTANT 
(Y represents colonies normal to X) 
September, 1913 
. a X2 Isolation culture 
“ “ 
Aug.—Sept., 1914 X4 Isolation from X3 
“ec “e “ae X5 “a ax 
a ms Y6 Isolation from Y5 
ae ae ae X6 ae ae ES: 
ae “ee oe G7) 4“ oe X6 
se “e ce DES 4“é “e XG) 
X1 First colony of mutant X 
X and Y types present. 
X3 Test tube culture of an X colony from X2 
WS Tube from a Y colony of X4 
X9-X13 Series of test tube cultures 
February, 1915 X14 Isolation from X13 
X15 & X16 test tube cultures 
Feb.—April, 1916 
: Xai2 “ oe wl 
ae “sé ae Xal3 ae ae Xal2 
“e “é “ee Xal4 ae ae Xal3 
X17 Isolation from X16 
Xal5—Xal17 Test tube cultures 
July, 1917 
alee Maly i 
Xai18 Isolation from Xal7 
Xal6 
96X :119Y 
OX : 481Y 
512X Beis (GPs) 
625X : OY 
316X : OY 
HEPES A ENE 
OX : 204Y 
5X :56Y 
INDI 
678X :3Y 
-OX : 207Y 
OX : 473Y 
A RANDOM TEST IN THE THEORY 
OF PROTECTIVE COLORATION 
FREDERICK ADAMS Woops 
oped the theory, noone supposed 
that the bright and often daz- 
zling colors of birds and other animals 
were in many instances a device to 
render these creatures not more but 
less conspicuous. Rem mbrance of the 
wide introduction of camouflage and 
dazzle-painting during the late war will 
doubtless do much to convince the 
skeptical of the essential truths of 
Thayer's theories—discoveries which 
were in their essence optical, and did not 
necessarily involve learned discussions 
in natural history. 
In Thayer's elaborate and magnifi- 
cent book on the subject of protective 
coloration, a large number of black-and- 
white, and sometimes colored, pictures 
are presented by way of proof, but inas- 
[ NTIL Abbott Thayer had devel- 
1 Thayer, G. H. and A. H., 
much as the authors! have been accused 
of being over-zealous in finding support 
for their theory, some impartially, and 
accidentally acquired evidence is not 
without interest. 
Such evidence can now be supplied 
by museum material. In the old days, 
natural history museums were dismal 
places to visit. Stuffed animals, usually 
moth-eaten, were kept in dark and 
dusty cases, scientifically labeled and 
seldom seen. Now we have in many of 
the larger museums beautifully and ac- 
curately constructed artificial back- 
grounds as suitable settings for the 
wild life exhibited (as if in nature) and 
surrounded by natural objects—leaves, 
twigs, stones, and sand. 
The four pictures, here presented, 
were taken in the Museum 'of the Bos- 
“Concealing Coloration in the Animal Kingdom,” 1909. 
£ 
