168 
it even now is before overtaking the value of 
the lint, especially in long staple varieties. 
No compensating increase in the yield of seed 
is to be expected from a lintless cotton, the 
fiber being merely cellulose, like the woody 
tissues of the plant. 
Picking a lintless cotton by hand would be 
out of the question because the seeds fall out 
as soon as the bolls open, but possibilities of 
avoiding this difficulty have been suggested by 
the fact that all varieties do not open the bolls 
to the same extent or with equal readiness. 
Certain foreign cottons have nearly indehis- 
cent capsules, as have some of the relatives of 
cotton, including the okra plant, which could 
be grown as a seed crop. Other factors that 
affect the opening of cotton bolls are heat and 
dryness. Full-grown bolls of Kekchi cotton 
remained fresh and apparently unchanged for 
nearly six months in a greenhouse experiment, 
and yet opened normally when the plants were 
taken outside and allowed to dry. The failure 
of bolls to open in cool autumn weather, which 
now appears as a danger or limiting factor of 
cotton culture in some parts of California, 
might be an advantage if harvesting by 
machinery were practicable. 
In considering the possibility of utilizing 
late-opening cotton in California it seemed 
that two kinds of machines would be needed. 
The first machine might be thought of as a 
modified corn-binder that would cut or pull 
the plants, and at the same time press and tie 
them into loose bundles or small bales, not 
too large to be handled easily nor too dense to 
dry without rotting. The bundles could be 
kept rather narrow, since the form of the 
plants can be controlled by methods of spacing 
and thinning that have been worked out. 
The stalks would be in the middle of the 
bundle, while most of the bolls would be on 
the outside, so that gradual drying and normal 
opening might be expected. 
As the plants would be pressed flat in the 
bundles they should come out in convenient 
shape for running into another machine for 
picking the seed cotton from the bolls. Rela- 
tively slight adaptations of existing types of 
picking machinery might serve, the problem 
SCIENCE 
[N. S. Vou. XLVIII. No. 1233 
in this form being much simpler than that of 
picking cotton from live plants in the field, 
which many inventors have attempted to solve. 
Gumming of the machinery and staining of 
the fiber with the plant juices would be 
avoided, as well as the difficulties of operating 
and repairing very complicated machines in 
the field. 
That machine picking could produce grades 
equal to those of cotton picked carefully by 
hand is hardly to be expected, although the 
quality might not be seriously impaired, if 
admixture with weak, immature fiber can be 
avoided. This might be possible in parts of 
California where the bolls are not likely to be 
frozen, though the leaves may be killed. 
Cleaners and gins could be operated in con- 
nection with stationary picking machines, and 
utilization of the stalks for paper-making or 
other industrial purposes would become more 
feasible. Leaving the fields clear at the end 
of the season would facilitate the planting of 
other crops, and might have advantages in 
relation to pests or diseases. Even with 
cotton considered as a seed-crop, the possibili- 
ties of mechanical harvesting do not appear 
to depend upon the breeding of lintless va- 
rieties. Special characters, conditions, or ap- 
pliances that might be expected to facilitate 
the harvesting of lintless cotton seem likely to 
be more useful in connection with lint-bear- 
ing varieties. 
O. F. Coox 
BuREAU OF PLANT INDUSTRY, 
U. S. DEPARTMENT OF AGRICULTURE 
AN ASPECT OF THE RELATION BETWEEN 
ABUNDANCE, MIGRATION AND RANGE 
IN BIRDS 
THE steps by which a species of bird ex- 
tends its range or acquires specialized migra- 
tory habits are not known. They present 
problems of interest in themselves and wide 
bearing in other fields. The aspect of the 
matter here set down is at least worthy of con- 
sideration. 
The red-breasted nuthatch is a bird which 
breeds in the northern coniferous forests. 
Some years it sweeps south across the country 
in fall in considerable numbers, and it is ex- 
