CURRENT LITERATURE. 
BOOK REVIEWS. 
The abnormal formation of resin ducts.* 
Dr. Alexander P. Anderson has distributed separates of his thesis pre- 
sented to the faculty of the University of Munich for the degree of doctor of 
philosophy. The paper contains interesting matter for botanists, pharmacists, 
and foresters. A careful perusal of it however, leaves the impression that a 
large number of more or less interesting facts are here brought together, but 
without proper assimilation. This as be unavoidable because so little is 
known of the subject, too little to permit at this time any generalizations; for 
before the appearance of this paper little had been published upon the 
matter, the references to it being mostly incidental. 
Resin ducts occur normally in the wood of spruces, pines, and larches, 
and are normally wanting in the wood of balsams, hemlocks, and cypresses. 
Wood parenchyma (simple resin receptacles, Gdpp), according to Krause is 
present in the wood of all species of Abies. Hartig found a marked irregu- : 
larity in the number and distribution of resin ducts in certain conifers that 
had been attacked by Agaricus melleus. He also found that in spruces in 
which so-called double rings were formed on account of late frosts, there is a 
striking irregularity in the formation of resin ducts in such rings. In 1892 . 
J. Hortman made some comparative anatomical investigations on the shoots 
from a “witch broom” on Aédzes fectinata and the normal shoots of the same 
species, in which he found that in the abnormal formation of cortex there is 
great irregularity i in the structure and in the size, as well as a considerable 
increase in the number of resin receptacles. E. Mer found an abnormal 
formation of resin sepals in shoots of Abies sp.? as a result of the attacks of ‘ 
Wea. ‘assume that abnormal resin receptacles are present only when a 
_ the plant is in part or entirely pathologically influenced. If for example ae 
resin reservoirs be found in the wood of Aédies pectinata, they area sure 
indication of some pathological condition existing in the plant. Further, 
with ¢ ~ Present ee we ——- —— that resin is strictly an excretion, 
Tees a4 11ST ¢ f the plant. 
SANDERSON, ALEXAND! on p—tber abnorme Bildung von Harzbehaltern und 
_anftretende: anatomische _Veranderungen im Holze erkrankter Coniferen. — 
Zeitsch., 1896. 8vo. pp- 38, #5-7- 
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