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POPULAR SCIENCE MONTHLY. 



of individual facts, but in the employment of these facts in their 

 relations to the most general notions and their capabilities for the 

 foundation of new and more comprehensive theories a method of 

 investigation productive of the highest results in all departments 

 of biological science. One of the conclusions reached in this man- 

 ner, which asserts the " polarity " of the plant cell, is at present 

 beyond the general level of the subject. Polarity will doubtless 

 be recognized as one of the most important physiological proper- 

 ties of protoplasm when the advance of the subject makes its ap- 

 preciation possible. The researches of Vochting have dealt prin- 



TiiE Botanic Institute, View from Wilhelmstbasse. 

 After a photolitliograpli, by pemiissiou. 



cipally with the physiology of movement and what might briefly 

 be termed physiological morphology. 



The garden is located in the northeastern part of Tiibingen in 

 western Wiirtemberg, It lies at an elevation of about one thou- 

 sand feet, on the plateau encircled by the Schwarzwald, in latitude 

 48 30' north. Near it are hills covered with forests of pine, which 

 rise two hundred and fifty to three hundred feet above it, while to 

 the southward, twenty miles away, the Swabian Alps reach to a 

 height of twenty-five hundred feet, in consequence of which the 

 night temperature falls far below that of the day. A low win- 

 ter temperature of 30 C, and a summer limit of 25 to 28 C, 

 help to make a climate which resembles that of southern Michigan 

 in many respects. The area inclosed amounts to about two and 

 six tenths hectares of nearly level land on both sides of the banks 

 of the Ammer, a small tributary to the Neckar. The grounds are 

 planted in the system of Eichler, modified, however, to meet the 



