THE AMERICAN ENTOMOLOGIST. 



95 



ON OUR TABLE. 



Dr. J. T. C. Katzebiivg'.s great works on 

 " Forest Trees, their Diseases and Insect Ene- 

 mies," and liis worli on " Weeds of Germany 

 and Switzerland"— i>je Waldverderhniss (23 

 Thaler, gold) ; Die Standortsf/ewachse und 

 ITtikrcButer De.utschlands und der Schweitz (4J 

 Thaler); and Die Wuhlverderber und Ihrc 

 Feinde (4 Thaler). — Some time since we re- 

 ceived from L. Agassiz, through Dr. Uagcn, of 

 Cambridge, the foregoing splendid German 

 works for inspection and notice. These works 

 have not their equal iu the English language, 

 and with their superb illustrations and vast fund 

 of most desirable information, they should have 

 a place in the library of every college where the 

 (Jcrman language is taught. We would especi- 

 ally call the attention of the presidents of our 

 dillcrent agricultural colleges to these works. 

 The price of the three will probably cost over 

 $40.00 in America; but, in order to introduce 

 them into this country, the author has offered, 

 through his booksellers, to make a liberal de- 

 duction when more than one set is ordered, and 

 Dr. H. Hagcn, of Cambridge, Mass., has con- 

 sented to i-eceive subscriptions. The books 

 were accompanied with the following notice 

 from the pen of the last named gentleman, 

 which we gladly make room for, as it contains 

 valuable suggestions, and we have ourselves 

 only found time to hastily glance over the 

 works: 



Wood, and forests which proUuce wood, form almost 

 as imiiortant a part of tlie natural wealth of a country 

 as do metals, coal, and other minerals. In some views 

 wood is even the more important article, since without 

 nuiod m cullnre is posHUe or imayinalle . "Wood cannot 

 in «?/ eases be replaced by iron or other bodies. Hence, 

 we rind tliat the regions which are entirely or in part 

 destitute of wood never attain to a cultivated condi- 

 tion (large tr.acts of Africa, Asia, etc.), wliile, on tlie 

 other liand, a superabundance of forests forms an im- 

 pediment to cultivation, as in many paits of Anniiii 

 It is only after the removal of tliis exii -s ili;ii .uliha- 

 tion progresses rapidly. Where nature oilers i-ielus in 

 great abundance, there the due standard of apprecia- 

 tion becomes lost; and any one who has seen how tlie 

 Mississippi steamers, as well as the railroads in the 

 East and West, are often fed with timber that is v.alu- 

 able lor all purposes, will admit that this is an abuse, 

 or, in other words, that expensive materials are thus 

 wasted . Every waste, however, brings Its consequence, 

 and in time necessitates a supply at high rates. There 

 can be no doubt that in a country densely covered with 

 pristine woods, the clearing must precede cultivation, 

 and this clearing has to be carried on in the most rapid 

 and most destructive manner, iu order to prove profit- 

 able for the moment. Uut then, afterwards a period is 

 sure to arrive when a stop has to be put to that devasta- 

 tion, in order to forestall want. There can be no 



doubt that, in America, that time has come, or has 

 even been transgressed, though the fact has not yet be- 

 come very palpable, for the reason that from other 

 parts, which are still well timbered, plenty of wood 

 can as yet be temporarily imported . A cessation of this 

 destructive practice is to be anticipated from an in- 

 creasing cheapness of coal as fuel for manufactories, 

 railroads, and steambo.ats; but this cessation will come 

 too late, in part, and generations to come will be sensi- 

 bly all'ected thereby; for it is a well known and very im- 

 portant fact that the same kind of timber that existed on 

 a tract once cleared, cannot be immediately producctl 

 again. Nature has managed it so that quite a numljcr 

 of processes of vegetation have to begone through with 

 liefore the original trees of the primev.al forest can re- 

 sume their rights. Under the tropics, as well as in 

 higli northern latitudes, this change is wrought in the 

 course Ola few generations, butin tlieintenneili:ite leni- 

 perate zones a much longer time isrequiiid. :\Inir..ver. 

 tlie species that immediately succceil tlio-,. whirli were 

 cut down are always such as furnish inrerioi- wood. In 

 America, which is endowed by nature with a great iiiun- 

 ber of species which afford the best wood for technical 

 purposes, this fact, uo doubt, becomes the more impor 

 taut. It appears to me that the very excellence of 

 American wood has essentially contributed to the rapid 

 advancement of civilization . A great number of skilled 

 pursuits are thereby essentially favored, since the firm- 

 ness and durability of its material admit of a delicacy 

 and care in their elaboration which, in Eurofie, is ren- 

 dered impracticable through the imperfection of their 

 wood . 



Add to this another circumstance — one which makes 

 this discussion suitable for the purposes of an entomolo- 

 gical paper : 



So long as nature alone is opeiating, it vei'y rare'y 

 (or perhaps never) occurs, that extensive damage to 

 plants and trees is wrought by Insects or other animals. 

 It is only iilter the natural relations are altered by hu- 

 man agencies, as, e. (/..by the burning down or clearing 

 of entire tracts, or by a subsequent compulsory forest- 

 culture, that noxious insects are multiplied in excess, 

 and require the energetic attention and interference of 

 mankind. We have lately had abundant proof of this 

 in Germany. The well-known Pine Bombyx {Iknnhi/j- 

 Jfunachu) had been harmless for about fifty years, when, 

 in Ls.'d, it reappeared. For three years little attention 

 was ]i:iiil to it, and interference was not attenqjted until 

 ii lia.l lieronie too late. The result can only now, alter 

 llir Uiniination of the calamity, be fully estimated. 

 Vi-inn till' Ural mountains through the entire width of 

 Itussia and Tolaud, and onward into the interior of 

 Prussia, 175,000 square miles were, in those years, itv 

 fested, and 5.1,000,000 cords of wood destroyed. In 

 East Prussia alone (of the size of the State of Massachu- 

 setts) 7,000,000 cords. I was myself an eye-witness to 

 interminable trains of butterflies on their way in search 

 of new breeding-places. In several cases they pa.ssed 

 over sounds of fifteen miles' breadth in search of intact 

 forests. 



I believe that, in America, there exists no indepen- 

 dent literature on this subject, and uo observations arc 

 on record. But it is quite plain that the experience of 

 other countries ciin be made aviiilable. The climate of 

 Europe is, in many respects, very simiKir to that of the 

 most richly wooded northerly States of the Union . The 



