138 TIMBER AND SOME OF ITS DISEASES. [CHAP. 



annual ring is less capable of conducting water than 

 the large-celled spring-wood of the same ring ; and 

 Errera implies that this is hardly what one would 

 expect if the imbibition theory were true. 



Notwithstanding the obvious tendency of the criti- 

 cisms given in the above, and previous papers, how- 

 ever, Sachs published a second edition of his Vor- 

 lesungen in 1887, in which he maintains his original 

 position, and scarcely notices any of the difficulties 

 which have been raised since 1882. The note on p. 

 225-226 can scarcely be regarded as a reply to what 

 has been urged by Elfving, Hartig, Westermaier, 

 Godlewski, and others, and it must be accepted that 

 the great botanist has nothing further to add in 

 support of his original hypothesis. 1 



From the experiments of Strasburger, who has 

 recently paid especial attention to this subject, and of 

 others, it now appears that a tree can continue to 



1 The reader who is interested in further criticism ou details should 

 consult the following memoirs : Zimmermann, ' ' Zur Godlewskischen 

 Theorie der Wasserbewegung in der Pflanzen," Ber. d. d. hot. Gesellsch. 

 1885, pp. 290-292. Hansen, "Em Beitrag zur Kenntniss des Tran- 

 spirationsstromes," Arb. d. bot. Inst. Wursburg, 1885, pp. 305-314. 

 Scheit, "Die Wasserbewegung im Holze," Jenaische Zeitschrift fur 

 Naturk, 1885, pp. 678-734. Schwendener, " Untersuchimgen ueber 

 das Saftsteigen," Sitzungsber. d. k. preuss. Akad. d. Wiss. 1886, pp. 

 561-602. Scheit, "Beitrag zur Widerlegung der Imbibitionstheorie," 

 Jenaische Zietschr. 1885. 



