248 FORESTRY [Box. Absts., Vol. X, 



1641. KoHSTiAN, C. F. Grazing practice in the national forests and its effects on natural 

 conditions. Sci. Monthly 13: 273-281. Fig. 1-7. 1921.— This is a brief statement of the 

 problems and conditions affecting the question of when and how much grazing may be allowed, 

 and of the advantages and disadvantages of forest grazing. — L. Pace. 



1642. Krausse, Anton. Beobachtungen an Dasychira pudibunda L. gelegentlich des 

 Eberswalder Frasses 1917. [Observations of Dasychira pudibunda in connection with the 

 Eberswald attack of 1917.] Zeitschr. Forst- u. Jagdw. 51: 265-272. Fig. 1-9. 1919.— The 

 species was observed in limited numbers in Eberswald during 1915 and 1916, and in the fall 

 of 1917 appeared in enormous numbers, devastating the beech forests and attacking the horn- 

 beam. Pine trees, too, were infested but no needles were consumed. No satisfactory expla- 

 nation has been offered for this infestation, migration being out of the question. The color 

 variation in the caterpillars was of interest, black ones being in the majority. All cater- 

 pillars were diseased ("polyederkrank"). The hair of the caterpillar produced no disagree- 

 able effects in contact with the skin, though it is generally considered extremely irritating. 

 [See also Bot. Absts. 10, Entry 1644.]—/. Roeser. 



1643. Krausse, Anton. Ennomos quercinaria Hfn. (Lep. Geom.) als Waldverderber. 

 [Ennomos quercinaria Hfn. (Lep, Geom.) as a destroyer of forests.] Zeitschr. Forst- u. Jagdw. 

 51: 153-159. Fig. 1-6. 1919. — This insect, reported as a forest pest for the 1st time in 1917, 

 appeared in the forest district of Saarbriicken. Suppressed beech were attacked first in May; 

 dominant trees, 80-100 years old, later. The pupa is easily identified by 4 large hook-like 

 appendages at the posterior end and 2 smaller appendages on each side nearby. The butter- 

 fly's habits and life history are described. — J. Roeser. 



1644. Krausse, Anton. tJber Dasychira pudibunda L. bei Eberswalde 1918. [Dasychira pudi 

 bunda in the Ebers forest in 1918.] Zeitschr. Forst- u. Jagdw. 51: 445-447. 1 fig. 1919. — 

 This is a brief account of further studies of Dasijchira pudibunda. All eggs, caterpillars, and 

 butterflies examined were "polyeder" diseased, though many individuals are apparently 

 immune. Although the disease caused terrific destruction during 1917, it did not prevent a 

 light devastation by this insect in 1918. — [See also Bot. Absts. 10, Entry 1642.] — J. Roeser. 



1645. LaVarre, W. Brazil's white gold. Sci. Amer. Monthly 3: 133-136. 5 fig. 1921. 

 [Abstract from Bull. Pan American Union 50: 462-476. 1920. — This is an account of the 

 primitive methods still used in collecting the milk of the rubber tree. — Chas. H. Otis. 



1646. LiNDSAT, H. A. F., and C. M. Harlow. Report on lac and shellac. Indian Forest 

 Rec. 8^: 1-162. 10 charts, 4 pl-, i map. 1921. — Despite its importance to India, lac is still 

 collected in a crude and wasteful manner, mostly from wild forest trees by ignorant native 

 villagers, and marketed without economic foresight. Scientific knowledge of the lac insect 

 and its hosts, of the physiological processes involved in lac production, and of climatic and 

 other influencing factors, is meagrte; and research has been unaccountably neglected. — The 

 lac insect, Tachardia lacca, sucks the juices of the host plant and produces an unusually 

 massive secretory or excretory incrustation. This is the amber-colored, resinous lac, from 

 which shellac is manufactured. The female insect lives about 6 months, and produces 2 

 broods of minute larvae, which emerge in "swarms" during the time the lac harvests are 

 made. Only the more obvious phases of the life history are known. In addition to the physi- 

 ological processes involved in lac formation, some of the problems awaiting solution are: 

 Effect (upon quality of lac) produced by the amount and quality of food obtained from the 

 6 or 7 major and 15 or more minor host plants; vitality and hardiness of the several strains 

 of lac insects and their efficiencj' as lac producers; effect of weather and climatic conditions 

 upon the efficiency of the insect; natural enemies of the insect and of the host plants. Con- 

 siderable work has been done upon the last question in the way of identifying the more im- 

 portant parasites of the lac insect; but little is known of their habits, life histories, and distri- 

 bution, or of their relative destructiveness, and means of combating them. The best lac is 

 the "kusmi," or winter crop, from the kusum tree (Schhichera trijuga) found in the sub- 



