1895.] Development of Botany in Germany. 203 
Besides Sachs, ROBERT HARTIG (of Munich), Schwendener and 
Strasburger have especially interested themselves in the prob- 
lems of the movement of water in the plant; while ALFRED 
FISCHER (Leipzig), and others have been concerned with the 
transfer of food-materials. Concerning the physiological phe- 
nomena of irritability, in addition to the fundamental labors 
of Sachs, the researches of WORTMANN (professor at the 
Academy in Geisenheim), of VOCHTING (Basel, Tiibingen),and 
especially of FR. NOLL (docent in Bonn), have found well 
merited respect.° An attractive presentation of our entire 
physiological knowledge was given in Sachs’s ‘‘Vorlesungen 
iber Pflanzenphysiologie,”® the first edition of which was pub- 
lished in 1882. The phenomena of the irritability of the liv- 
ing substance were there thoughtfully set forth, and their im- 
portance in the true estimation of the phenomena of life 
clearly elucidated. : 
Our knowledge of the reproductive processes has gained 
merely a firm morphological basis. Strasburger especially 
has contributed to this during recent decades. The physiol- 
ogy of reproduction is still, for the most part, on speculative 
ground; but it was notably advanced in 1884 by Naegeli’s 
mechanico-physiological theory of descent, in which the idio- 
plasm theory was first formulated. Naegeli’s observations on 
the production of bastards, on the conditions for the appear- 
ance of species and varieties, and his studies, extended 
through years, of the intermediate forms among the Hiera- 
ciums, are to this day important contributions to the phe- 
nomena of genera and development. 
Thanks to Darwin’s classical work on the arrange- 
ments for pollination among the orchids, the attention of 
students was directed to a very remarkable book by Christian 
Konrad Sprengel which, published in 1793, remained quite 
unnoticed and had practically disappeared. In all parts of Ger- 
many, workers turned their active attention to this subject, and 
In consequence, Sprengel’s assertions were generally con- 
firmed, often extended, and in many essential points given 
their correct significance. FR. HILDEBRAND (Freiburg in 
Baden) was the first to distinguish himself in this direction; 
but HERMANN MULLER (teacher in Lippstadt, died in 1883) 
*No one will doubt that Pfeffer’s name was only uniatentionally omitted, and 
bar it deserves inent place in this list. P. 
h 
a promin : he. 
ranslated and published in English in 1837.—G. J. P. 
