MASCHA] STRUCTURE OF WING—FEATHERS 3 
This list, although small, comprises birds of most types of flight, 
my aim being not to examine many different species but only rep- 
-resentatives of the different types. The remiges of Columba, 
Cypselus, and Diomedea were studied most carefully ; those of birds 
not capable of flight did not fall within the scope of my investiga- 
tions." 
I have taken no notice of the numerous new terms concerning the 
arrangement of the feathers proposed by Alix (1864, p. 10), Wray 
(1887, pp. 344-345) and others, the older divisions into hand- 
remiges and arm-remiges being quite sufficient for my purpose. 
It was to be foreseen that the treatment of such brittle and hard 
material as the horny substance of feathers would present serious 
technical difficulties. Former investigators have left no record 
of the way in which their examinations on developed feathers were 
conducted. It is true that Strong (1902, pp. 148-151) has described 
his mode of procedure rather fully, but he speaks merely of the 
treatment of “ feather germs.” 
I treated the material to be examined in the following manner: 
I took one of the three outermost hand-remiges, usually the longest, 
and one of the arm-remiges of each species of bird to be examined, 
and placed a portion of the vane on the slide mounted in balsam. 
Then one of the secondary quills was cut off and the tertiary 
fibers, attached to it, removed to the slide by means of a sharp 
scalpel. In this way large numbers of isolated tertiary fibers lying 
in different positions were obtained and mounted in balsam. Parts 
of white colorless feathers became so transparent in this medium 
that recourse to staining was resorted to. It should be noted that 
of the numerous stains tried, only two proved useful: picric acid, 
which quickly produced a yellow coloring, too faint however to be 
effective, and safranin, which stains a deep color and gives good 
results when properly applied. I used the safranin in a semi- 
alcoholic solution and left the objects in it from six to twelve hours. 
After being stained the feathers were dried and then further manipu- 
lated. The most difficult part of the work, but at the same time the 
one that gave the best results, was section cutting with the micro- 
tome, in which operation the fragility of the material proved very 
troublesome. The specimens were placed in chloroform to expel 
the air, and imbedded in paraffin or celloidin. In cutting the paraffin 
*The wings of birds not capable of flight have no hook fibers on the ter- 
tiaries, as their wings do not need to form such an impenetrable surface as 
is requisite in birds of flight. In the ostrich the tertiary fibers are entirely 
smooth (branchless) ; in the cassowary and the apteryx they show small thorn- 
like protuberances which are also present in the penguin, but somewhat longer. 
