( 449 ) 
At the opening of the flower the perianth, and especially the 
corolla, are in very different condition, the latter generally not having 
reached anything like its full size, when the sepals move apart. In 
a very short time, the corolla grows out to its normal dimensions, 
to be afterwards during the whole flowering period the seat of various 
physiological processes, consisting partly, in the transformation to its 
own use of material laid down in its tissues in the bud, and partly 
in the continuous production of fragrant vapours, which the flower 
gives off in that period, very often also in the production of nectar 
etc. If we further remember, that the considerable quantity of water 
which the corolla gives off to the atmosphere by transpiration, is con- 
tinually replenished by fresh supplies, while the stamens on the other 
hand receive less water from the thalamus than they give off, it 
becomes clear, that the nutrition-stream moves principally in the corolla. 
The consideration suggests the following questions: What means 
are at the disposal of the ovary for escaping the harmful consequences 
of too strong transpiration? Is the secretion of nectar perhaps to be 
regarded as one of these means? 
I venture to think that I have obtained an affirmative answer to 
the last question and hope that I may succeed in obtaining acceptance 
of my opinion. 
I wish to preface a description of the ponies and of nectar-secretion 
in Fritillaria Amper ialis. 
Fritillaria imperials bears large, bell-shaped flowers turned with 
the opening downwards, and consisting of a perianth of two trimerous 
whorls, a superior ovary with a long style and tripartite stigma, and 
6 long stamens, with filaments entirely enclosed in the bell, but with 
anthers protruding outside. Generally the style is somewhat longer, 
so that the stigmas are under the anthers and outside the flower. 
The cylindrical ovary escapes observation, as it is wholly surrounded 
by the fleshy filaments of the stamens, which form a close-fitting 
tube around it. 
Not until fertilisation has taken place and the perianth has withered, 
do the flowers become erect; the fruits afterwards are also erect. 
Each perianth-leaf bears close to its base a large saucer-shaped, 
shiny, white nectary, which is surrounded by an elevated border, 
and secretes heavy drops of fluid during the flowering-period. 
The whole of the perianth is very rich in glucose, not only at 
the time of flowering, but already much earlier. A section through 
the middle of an adult perianth leaf, about half-way between base 
and top, shows, that the mesophyll, which is here 13—14 cells thick, 
