REVIEWS. 
523 
Tectona Grandis, L.—This species, in Buitenzorg, is never completely 
leafless, but retains a crown of leaves, though in East Java it passes 
through a leafless phase. The rings of growth in trees grown in East Java 
are more complete and distinct than those of trees grown in Buitenzorg. 
The climatic periodicity in East Java leads to a definite leaf-fail and 
zoned formation in the xylem. The rings are not necessarily annual, 
and wtien not complete are due to local activity of the cambium. The 
zone formation increases in sharpness in a centrifugal direction, 
probably on account of the defoliation in the early years being less 
complete than in the latter years. Observations in Ceylon have shown 
that certain species do not become defoliated annually until they have 
attained a certain age, and this may prove to be the case with teak. 
Poinciana Regia , Boj.—Trees of this species are never, according to 
Smith, entirely leafless in Buitenzorg, though they are conspicuously 
so in East Java, and the rings of growth in trees grown at the latter 
place are more complete and distinct than those grown in Buitenzorg. 
I may add that at Peradeniya young trees are completely leafless every 
year, though old trees are sometimes only partially so. 
Eriodendron anfractuosum , D.C.—Trees of this species are leafless at 
Buitenzorg and East Java, though the rings of growth are more distinct 
in the latter than the former place. At Peradeniya the trees drop 
their leaves in the first year. 
Albizzia moluccana. — This is practically an evergreen tree with a 
definite foliar periodicity, and at Buitenzorg and East Java is never 
leafless, though at the latter place the rings of growth are more 
conspicuous than at Buitenzorg. 
These observations prove —(1) that in Java the effect of a dry period 
is to make the zone formation in the wood sharper and more complete ; 
(2) that defoliation is not necessarily the only phenomenon, which will 
lead to the production of zones in the xylem, (3) in the same climate 
at Buitenzorg the sharpness of the rings of growth varies, and putting 
them in order, with the sharpest first and weakest last, we have the 
following : Tectona grandis, Poinciana regia, Eriodendron anfractuo¬ 
sum, Odina gummifera, Melochia indica, and Albizzia moluccana. 
_ H. W. 
ianuaB of the Trees of Stiorth America. 
By Charles Sprague Sargent. (University Press, 
Cambridge, 1905.) 
This book deals mainly with the characters of temperate zone trees. 
A map of North America (exclusive of Mexico) showing the regions 
into which the country is divided according to the prevailing character 
of the trees, and a glossary of technical terms are given. An analytical 
key based on the character of the leaves has been made, and the book 
is well illustrated on almost every page. 
H. W. 
