HISTORICAL DEVELOPMENT OF FLOWER POLLINATION 21 
und die gegenseitigen Anpassungen beider’ (Leipzig, 1873), which meanwhile appeared, 
was of remarkable importance for the study of Flower Pollination. It was followed in 
1881 by Miiller’s second great work, ‘Alpenblumen,’ and in 1878-1882 by his third— 
‘Weitere Beobachtungen iiber die Befruchtung der Blumen durch Insekten.’ These 
works embrace not only an amazing number of individual observations with reference 
both to the floral arrangements of many hundreds of plants and also to the visits 
of many thousands of insects, but they also furnish evidence for the floral theory 
established by the author. The principles enunciated by Knight, Darwin, Hildebrand, 
and Delpino offered no explanation of the numerous known instances of fruitful 
self-pollination, including cases of cleistogamy. For the one-sided ‘Law’ of the 
above-named investigators—a Law that was not universally proved,— Miller substituted 
the following statement, the drect proof of which rested on Darwin’s experiments, 
while the zzdzrect proof was based on the floral arrangements of plants in general, 
and, more particularly, on adaptations in the flowers themselves: Whenever progeny 
resulting from crossing comes tnio sertous conflict with the offspring resulting from 
self-fertiligation, the former ws victorious. Only where there ts no such struggle for 
existence can self-fertilization often prove satisfactory for many generations. 
That direct and indirect proofs attest the correctness of this great law of life 
has already been stated. They are given as follows by Hermann Miller (in 
‘Alpenblumen,’ pp. 474-5):—‘In the flowers investigated in this connection, it 
appeared, as first shown at any length in ‘Die Befruchtung der Blumen durch 
Insekten,’ to be a general rule, offering only a few easily explained exceptions, that 
flowers to which insect visits are constant and sufficient, are adapted exclusively 
for crossing by the insects, and that, on the contrary, in proportion as insect visits 
are uncertain, the floral arrangements permit or favour spontaneous self-fertilization. 
It appears from the direct experiments of Darwin, as well as from the pollination 
University of Halle to study Natural Science. He devoted himself here chiefly to Geology, to which 
he also applied himself enthusiastically in Berlin, during his stay there from 1849 to 1852. In 1852 
he passed the Examination pro Facultate docendi and spent the following winter in the house of his 
parents. In 1853 he made his first journey to the Alps, this being chiefly undertaken in furtherance 
of his geological studies, though he also did something in the way of collecting plants and insects. 
From Michaelmas, 1853, till the following Michaelmas, Miiller spent his year of probation in the 
Friedrich- Wilhelm Gymnasium at Berlin. Next winter he took the place of a teacher in Schwerin 
who was sick. His first journey in the Alps had aroused in him an appreciation for the rich flora 
and fauna of the Highlands, and in 1855 he undertook his second alpine journey, and this was 
specially devoted to Botany and Entomology. In the same year Miiller was called to the Realschule 
in Lippstadt, which was then in course of formation. In 1856 he was definitely placed on the staff 
of this institution ; in 1865 he became upper-master; and in 1883 he received the title of Professor. 
The ‘ Origin of Species,’ and Darwin’s book on Orchids had so great an influence on Hermann 
Miiller, that from 1866, the year in which he became acquainted with these works, he devoted his 
knowledge, his energy, and his power of research wholly to Pollination. In 1873 appeared his first 
great work, ‘ Die Befruchtung der Blumen durch Insekten’; in 1881 his second, ‘ Die Alpenblumen’ ; 
from 1878 to 1882 his third, which forms a completion to the first, ‘ Weitere Beobachtungen tiber die 
_Befruchtung der Blumen durch Insekten.’? Hermann Miiller died on August 25, 1883, of pulmonary 
disease, while travelling in the Tyrol in pursuit of Science, and for the benefit of his health. A full 
account of his life, and of his services to Pedagogy, and more especially to Pollination, is given by 
F. Ludwig in the Bot. Centralbl., 1884, vol. xvii, pp. 393-414, under the title ‘ Das Leben und Wirken 
Professor Dr. Hermann Miiller’s.’’ See also E. Krause in the work, ‘ Hermann Miiller von Lippstadt. 
Ein Gedenkblatt. Lippstadt, 1884.’ 
