6i 



Herbaria representing the general fungus flora of different countries, as, 

 for example, those by Saccardo, Sydow, \"estergren, J. B. Ellis, Jaap, Bubak 

 and Kabat, Posch etc. 



Although the science of plant diseases would refer to teratological phe- 

 nomena only when it can prove, or at least suppose as a cause of the indi- 

 vidual phenomena, some definite disturbance of nutritive or structural con- 

 ditions, it has been forced to take the animal world more and more thor- 

 oughly into consideration. The following publications summarize the entire 

 material or the larger part of it, are comprehensive and should be used for 

 further study: — Ratzeburg, "Die Forstinsekten," Berlin 1839-1844 and "Die 

 Waldverderbnis," Berlin 1866-1868; A Gerstacker, "Handbuch der Zoolo- 

 gie," Vol. II., Arthropoden, Leipzig 1863 ; E. L. Taschenberg, "Entomo- 

 gie fiir Gartner und Gartenfreunde," Leipzig 1871, and "Die der Landwirt- 

 schaft schadlichen Insekten und Wiirmer," Leipzig 1865. Further Nordlinger, 

 "Die kleinen Feinde der Landwirtschaft," Stuttgart 1869. Kaltenbach, "Die 

 Pflanzenfeinde ans der Klasse der Insekten," Stuttgart 1874, and Ritzema 

 Bos, "Tierische Schadlinge und Niitzlinge," Berlin 1891. The "Handbook of 

 the Destructive Insects," by C. French, published in Melbourne in 1891 by 

 order of the Department of Agriculture of Victoria, is less rich in material but 

 better adapted to the practical needs of the layman, because of its colored 

 plates. 



In the same year H. R. v. Schlechtendal published a smaller special work 

 on gall formations. — ^"Die Gallbildungen (Zoocecidien) der deutschen 

 Gefasspflanzen," Zwickau 1891. Ten years later G. Darboux and C. Houard 

 published a comprehensive systematic work, — "Catalogue systematique des 

 Zoocecidies de I'Europe et du Bassin mediterraneen," Paris 1901. 



The "Forstliche Zoologie" by K. Echstein, Berlin 1897, "lay be 

 especially recommended because of many careful original drawings. The 

 popular writings of H v. Schilling are especially useful for horticuhure ; 

 we recommend "Die Schadlinge des Obst-und Weinbaues," "Die Schadlinge 

 des Gemitsebaues," Frankfort a. O. 1898 and the "Practischer LTngezieferk- 

 alender," Frankfurt a. O. 1902. The "Schutz der Obstbaume gegen feind- 

 liche Tiere" by E. L. Taschenberg (3rd Edition by O. Taschenberg), Stutt- 

 gart 1901, is also well adapted for practical needs. 



As the science of plant protection develops there is a corresponding at- 

 tempt to produce reference books treating some of the most important culti- 

 vated plants, such as Eisbein "Die kleinen Feinde des Riibenbaues, 1882, with 

 carefully prepared colored plates and Emile Lucet "Les insectes nuisibles 

 aux Rosiers sauvages et cultives en France," Paris 1898, with numerous 

 plates in black and white. Most complete is the work being done in the 

 United States in protecting plants from these animal enemies. The Zoolo- 

 gists in the several State Experiment Stations and the "Bureau of Entomol- 

 cgy" of the Federal Department of Agriculture in Washington, are advanc- 

 ing rapidly the study of the enemies of cultivated plants, by new investiga- 



