parti] § THE MECHANISMS OF FLOWERS. 99 
stigma if the bee comes from another flower. Hildebrand’s 
experiments prove that the flowers of C. ochroleuca are fertile both 
with their own pollen and with that from another flower of the 
same plant. 
25. CoRYDALIS LUTEA, D.C., resembles C. ochroleuca in the 
mechanism of its flower. I saw it repeatedly visited and sucked 
in the legitimate way by Bombus agrorum, F. 2, whose proboscis 
measures 12 to 15 mm. Other bees which I have seen visiting the 
flower are enumerated in my Weitere Beobachtungen, pt. i. p. 54. 
cam 
26. FUMARIA OFFICINALIS, L.—The mechanism of the flower 
resembles that of Corydalis cava ; but the flowers are much smaller, 
and instead of the long spur, a short rounded pouch is present 
in which a short process from the upper stamen is lodged and 
secretes honey. Hildebrand found the flowers to be fertile to their 
own pollen; but he doubts whether self-fertilisation often occurs 
under natural conditions, and places full reliance on the agency 
of insects. 
I have often watched J/. officinalis, and have convinced myself 
most clearly that it is very sparingly visited by insects. I have 
“only occasionally observed the hive-bee sucking at this flower, 
and I have very frequently watched in vain even in calm sunny 
weather for a single insect visitor. 
It is Sasi ale advantageous to a plant for its flowers to be 
adapted for fertilisation not by one or a few, but by many species 
of insects. In Fumaria officinalis, whose flowers might be visited 
by most kinds of bees on account of the shallow situation of the 
honey, this advantage which it has over C. cava is outweighed 
by several disadvantages. For C. cava blooms in early spring at a 
time and in places hers few flowers compete with it in attracting 
insects (its chief rivals on Stromberg Hill are Primula elatior and 
Pulmonaria officinalis); while Fumaria officinalis blooms in the 
middle of summer when many flowers at the same time are trying 
to divert the attention of honey-seeking bees. And further, while 
C. cava with its handsome spikes of flowers is very conspicuous 
in comparison with its neighbours, and displays a rich booty of 
honey and pollen to its guests, the small flowers of Fumaria 
officinalis are very inconspicuous In comparison, and give but a poor 
promise of spoil. Hence we see that although the honey of 
Corydalis cava can only be reached legitimately by one out of the 
‘tnany species of bees that are on the wing during its flowering 
H 2 
