270 NATURAL SCIENCE. APRIL, 
and more and more forced into the seclusion in which we have already 
seen him. He was beloved, however, by his pupils. 
On Sundays he usually conducted botanical excursions to the 
country round Berlin; any one might join these trips on payment of 
two or three groschen. On these occasions Sprengel was not merely 
a botanist, but would give instruction in anything that turned up. 
‘¢ He explained equally well the inscription on a tombstone, the con- 
struction of a windmill, the course of the stars, or the structure of a 
plant. . . . Knowing the country well, he led us always to places » 
where rare or remarkable plants were to be found. There were few 
places where he had not himself found something new, or noticed 
something special, and he gladly took the opportunity of leading us 
thither. Thus he showed us at one place the divided sexes of Mentha 
aquatica, which he had noticed there first, and afterwards observed 
in other species of Mentha... . In the Zoological Garden the 
Scrophularia gave him opportunity to explain dichogamy (see below). 
He was firmly convinced of the fertilisation of most flowers by insects, 
and he could, on this theory, so clearly explain the structure of 
flowers that it was a pleasure to watch and to listen to him... 
The commonest plant became new by what he had to say about it; 
a hair, a spot, gave him opportunity for questions, ideas, investiga- 
tions. Much remained a mystery to him; he was most exercised 
over the structure of Pavnassia. Here he was unable to catch nature 
in the act.” 
Towards the end of his life he abandoned botany and devoted 
himself entirely to languages ; he took up English, and was full of its 
great advantages. ‘‘ He often said that Linnzeus did not understand 
Greek, and had brought many errors into the nomenclature. He also 
blamed Willdenow for introducing the long and incorrect name 
Pelargonium, which should have been Pelargium.” He died in Berlin 
in 1816 at the age of 66. 
The chief interest of Sprengel’s life centres in his famous book 
‘“Das Entdeckte Geheimniss der Natur im Bau und in der Befruch- 
tung der Blumen ” (The Secret of Nature discovered, in the structure 
and the fertilisation of flowers). This was published in 1793 asa 
quarto volume of 222 pages, with 25 large copper plates, the latter 
being wonderfully accurate and well executed. In this volume 
Sprengel gives details of his observations on most of the wild flowers 
round Berlin, and many cultivated ones, all leading to the general 
conclusion that flowers are, mostly, adapted for fertilisation by 
insects. He shows how the insects are attracted, rewarded for 
coming by the honey, &c., and how almost every minutest structure 
in the flower, down to hairs and spots on the corolla, can be explained 
1 This plant is gynodicecious, /.c., bears upon some plants large hermaphrodite 
flowers, and on other plants smaller female flowers with aborted stamens. The 
same phenomenon is seen in many other plants of the order Labiate. 
