84 DR. G. KING ON THE GENUS FICUS. 
undulate surface. External to the crustaceous coat there is 
occasionally a glairy or viscid layer. The pericarp is never very 
thick, and sometimes it is conspicuously thin. On cutting the 
seed open the embryo is seen with a small amount of albumen; 
I have not, however, paid much attention to the relation of the 
' albumen to the embryo. Not a few of the perfect female flowers 
fail to be fertilized ; but the fact of the barrenness of such is not 
recognizable until the achene has been cut open, and it is found 
to contain no embryo. Externally these barren achenes exactly 
resemble those containing seeds. 
Besides the above four kinds of flowers, there occur in all the 
species of Ficus which I have examined a set of flowers which, 
adopting the name given to them by Count Solms-Laubach, I call 
gall-flowers. My own name for these was originally insect- 
attacked females ; but Count Solms-Laubach’s name being much 
shorter and more suitable, I have adopted it. The existence of 
these gall-flowers in this genus, as a separate and distinct kind 
of flower, was first made publicly known by the distinguished 
botanist just mentioned in the ‘ Botanische Zeitung,’ Nos. 33-36 
for 1885. My own observations and inquiries on Ficus have been 
in progress since 1878; but on account of my unwillingness to 
publish anything until I had completed my research, I have been 
anticipated in the publication of the facts about gall-flowers. The 
gall-flowers in many respects resemble the fertile female flowers; 
they have in most cases a similar perianth, an ovary, and a style. 
When fully developed, they are recognized at a glance by their 
containing the pupa of an insect, which can often be seen through 
the pericarp of the false achene into which the ovary develops. 
But whether the pupa be visible or not, or whether it be present 
or not, the false achene of the gall-flower may in its later stages 
be distinguished from the true achene of the fertilized ovary of 
the perfect or fertile female flower by being more often pedicellate, 
and by its shape being usually globular and rarely elliptic or 
reniform ; by its surface being smooth, not minutely tubercular 
or undulate, and never viscid or glairy ; and frequently also by 
the tense distended appearance of its tough membranous wall 
(false pericarp). The style is,as a rule, much shorter and 
straighter than the style of the fertile female, and more terminal, 
and it has very frequently a dilated tubular apex which occupies 
the situation of the true stigma, but has often little or none of 
the viscid parenchyma characteristic of that organ. These pecu- 
