CAPRIFICATION OF THE FIG. 93 
wasp—the Blastophaga grossorum. ‘These gall flowers do not produce 
seed, though in general aspect they resemble the female flower. 
The petals in the gall flowers are smaller and more unequal in size. 
The chief difference, however, between these flowers and the female 
flowers is found partly in the style of the pistil, which is not so elon- 
gated as in the female flowers, and partly in the stigma, which is very 
much smaller and entirely wanting the glands on its upper surface. 
The gall flowers can not be pollinated, or, if they are, the pollen does 
not develop pollen tubes, nor does the embryo or egg in the lower 
parts or ovary become fertile. A comparison of the figures of the gall 
flowers and female flowers will show the points of difference and 
resemblance. (See figs. 13 and 15.) ; 
While it is true that the gall flowers do not produce seed, it is a 
fact that they develop to a certain extent if punctured by the wasp, or, 
more correctly, if the egg of the Blastophaga wasp has been properly 
deposited. They then develop into galls—that is, the lower part of 
the stigma swells up and the 
integuments of the embryo 
sac harden, forming a glossy 
and brittle covering as a pro- 
tection for the larvee of the 
wasp. 
Those gall flowers which 
are not thus wounded by the 
Blastophaga egg do not de- b 
velop any further, but at once Fic. 13.—Seedling from seed of imported Smyrna 
wither and shrink up. Gall figs raised by E. W. Maslin, cut May 15, 1893: a, 
flowers are found in all wild- Sees, section of fig; b, gall flower; c, male 
fig species, though in some 
species their nature is not apparent until the egg of the Blastopuaga uas 
been laid. In the edible fig no gall flowers have been found with cer- 
tainty; at least the Blastophaga wasp, for whose special benefit these 
gall flowers seem to have originated, has never been found breeding in 
the edible figs. It has been supposed that the cause of this was to be 
found in the sugary juices of the edible fig, which killed the eggs or 
embryo of the wasps, but I am satisfied that this is not exactly true. 
Many varieties of wild-fig species produce very sweet fruits, edible 
and quite palatable, and still these figs serve as homes for Blastopha- 
gas. The cause of the inability of the wasp to breed in common figs 
must be sought for elsewhere, and, as I will presently point out, is 
due to the fact that the edible figs contain only flowers modified to such 
an extent that they are unsuitable as breeding places for the wasps. 
The gall flowers are characterized by a much shorter style, by an 
undeveloped stigma devoid of receptive glands, and by an imperfect 
embryo which never develops to more than a certain limited degree. 
The discovery of the distinction between gall flowers and female 
flowers is due to Solms-Laubach. 
