ON THE FLOWERS OF EUPHORBIA AMYGDALOIDES. 197 
372 flowers less, or I had better say it has lost one flower-head 
from each original peduncle, making 23 flower-heads less, containing, 
as before stated, 372 flowers. If these missing flower-heads were si- 
milar to the flower-heads remaining on the plant, the descriptions 
alluded to would be correct, but from an examination of a large num- 
ber of specimens I am prepared to say positively they are not the same; 
for whilst all the other flower-heads on the plant consist of single 
females surrounded by males, these 23 original and first opened involu- 
cres consist of male flowers only, without having in any single instance 
a female in the centre. As soon as the pollen is shed out of the anthers 
of these particular flowers their function is ended, and as there is no 
ovary they soon wither away. By the time the ordinary male and 
female flowers appear, they have entirely disappeared, leaving not -a 
trace behind. 
Did these deciduous flower-heads play no part in the economy 
of the plant they might be considered of little importance, but 
I am inclined to believe they are of extreme value. In the first 
place, not only do they* permanently differ in the shapes of the horns, 
etc. of the involucre, but all my observations tend to prove that these 
transitory, fleeting, and short-lived group of flowers are the only ones 
that bear fruitful pollen, and that all the females that are fertilized are 
fertilized by them. 
An ordinary flower-head of males and females, with the involucral 
leaves removed, presents always (in the early state) and when the ori- 
ginal flower-head of males is open, the truly extraordinary appearance 
of a flower in bud, with the pistils protruded through the top, the invo- 
luere tightly binding it round the base of the pistils, so that the stamens 
cannot get out. The stamens are bound down and twisted in the bud, as 
shown in section of the same flower-head, and as if to make it more im- 
possible for any of its own pollen to get to these stigmas, the small 
opening at top, where the pistils emerge, is packed with extremely fine, 
almost invisible hairs. Now, when the anthers of the flower-head of 
males are ready to shed their pollen they no longer remain inside the 
involucre, bnt elongate themselves, so that they stand bodily out, and 
display a joint in the filament of each; at this particular time the 
involucral leaves that enclose the head of flowers with the female 
slightly open, and display the stigmas; the pollen from the original 
flower then falls and fertilizes the ovules of the female, or the slightest 
