Ave6ust 30, 1918] 
yellow pine in northern Arizona and New 
Mexico. Most of the cacti in the United 
States are restricted to the southwestern area 
of late summer rains, and the same might be 
said of the species of Yucca and related gen- 
era.!2 (Both groups consist entirely of ever- 
greens, and both have also several representa- 
tives in the Southeast.) The gymnosperms 
other than conifers (7. e., Taxacee, Cycadacer, 
Gnetacex), as well as the palms and Ericacee, 
show a somewhat similar preference for late 
summer rain, in the United states at least. 
The same precipitation factor seems to con- 
trol indirectly several economic features. For 
example, most of the developed water-powers 
in the United States are within two or three 
hundred miles of the line of equilibrium be- 
tween early and late summer rains, though 
this may be chiefly because the same topo- 
graphic factors that make the water-power 
possible also influence the seasonal rainfall in 
some way. Some correlations between sea- 
sonal rainfall and crops are easily made. AlI- 
falfa, wheat, figs and upland cotton are not 
raised much where the late summer rainfall 
exceeds that of early summer by more than 
three inches, while sugar-cane, pineapples, 
grape-fruit and sea-island cotton thrive where 
late summer rains prevail. But of course the 
soil has a great deal to do with this too. 
It would be interesting, and comparatively 
easy, to determine how far the same seasonal 
precipitation factor can be correlated with 
soils, vegetation, ete., in other parts of the 
world. The explanation will not be quite so 
easy, for cause and effect are involved in a 
complex manner. Some of the marked soil 
differences between the Mississippi valley and 
the Atlantic coastal plain can be explained 
very well on geological grounds, wholly inde- 
_ pendently of modern climatic factors; and it 
may be that the deciduous forests and prairies 
that characterize the richest soils are con- 
ducive to early summer rains, and vice versa, 
in some way not yet understood. 
The factor here discussed probably does not 
have exactly the same significance in cold as 
12 See Plate 99 in the 13th Annual Report of the 
Missouri Botanical Garden, 1902. 
SCIENCE 
211 
in warm climates, in humid as in dry, or in 
regions of wet winters and dry summers, like 
the Pacific coast, as in regions with wet sum- 
mers, like Florida. All this deserves further 
investigation; and it may be found that by 
shifting a little the periods compared more 
significant results can be obtained.1% 
Rotanp M. Harper 
CoLLEGE Pornt, N. Y. 
PLANS FOR THE PHYSICAL RECON- 
STRUCTION OF DISABLED SOL- 
DIERS! 
Tue Surgeon-General, with the approval of 
the General Staff, announces the completion of 
plans for the physical reconstruction of dis- 
abled soldiers in the general military hospitals. 
These plans are formulated with a view to close 
cooperation with the War Department com- 
mittee on education and special service in the 
work of restoring men to full or limited mili- 
tary service, and with the Federal Board for 
Vocational Education, which is authorized by 
the law to provide vocational training for dis- 
abled men after their discharge from the army 
and navy. 
The records of 516 cases treated in four 
hospitals shows 1384 men able to return to full 
military duty, 210 fit for limited service, and 
172 who are eligible for discharge. In the last 
group 12 are classed as helpless or institu- 
tional cases; 121 are able to return to their 
former occupations; and 39 will need further 
training to fit them for earning a livelihood. 
These figures show the division of responsibil- 
ity in the work of reconstruction. 
The task of fitting men for further military 
service is at present the most pressing need be- 
cause wherever an able-bodied man behind the 
lines can be replaced by one less fit physically, 
but vocationally capable, a soldier is gained 
for active duty. The reconstruction work in 
the hospitals, therefore, will emphasize tech- 
18 The interested reader would do well to consult 
Professor R, DeC. Ward’s paper on rainfall types 
of the United States, in the Geographical Review 
for August, 1917, and some of the earlier litera- 
ture referred to therein and in the two pages fol- 
lowing it. 
1 Publication authorized by the War Department. 
