152- THE PLANT WORLD 



should greatly accelerate work along these lines. Besides 

 serving as an introductory text book of convenient size and 

 completeness for the student who has not previouslv worked 

 in this subject, it will surely have a marked effect toward 

 putting an end to much of the unhappy vagueness and 

 obscurity of thought which has fallen to the lot of exper- 

 imental morphologv, as to that of all newly cieveloped 

 branches of science. 



The author disavows all claim to completeness in his 

 treatment of the subject anci its literature. The book is to 

 be considered as an introduction rather than as a handbook. 

 Little attention is given to the ciirect influence of light, grav- 

 itation et cetera, which ha\'e been treated so fullv in Pfeffer's 

 Physiology and In Goebel's own Organography. Also, the 

 main considerations are here with the higher plants, such 

 as are found in gardens and plant houses and are thus of 

 comparati\cly easy access. In a \ery large measure the 

 cases described are from the authors own experiments, so 

 that the reader must feel that these chapters take him Into 

 the author's plant houses and garden, not merely into his 

 library. Most of the numerous figures, which really Illustrate 

 the text, are also original. The theoretical considerations 

 are confessecily of a simplicity which will prove ciisappolnting 

 to those who have already worked with these problems, 

 but my judgment in this regard is that these simple hypoth- 

 eses have not only the virtue of being admirably suited to 

 the needs of the beginner, but also the added one of being 

 logically safe as far as they go. They leave the reader free 

 to advance farther as his facts and logic will allow. 



In considering the influence of external conditions upon 

 the form of the plant, Goebel points out that these condi- 

 tions must always be active through Internal changes. The 

 simplest method of thinking of these internal conditions is 

 to view them as nutritive phenomena, and throughout the 



1. "Goebel, K.. Einleitung- ir. <iie experimentelle Morpliologie der Pflanzen 

 pp. Vni^260, fiss. 135. Leipzig- and Berlin. B. G. Teiilmer. 190S. 



