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POPULAR SCIENCE REVIEW. 
form of the pollen and the mode of pollination was brought out 
in a recent examination of perfect flowering specimens of the 
u Kerguelen’s Land Cabbage ” sent home from the Challenger 
expedition, who had used it largely as a vegetable while in those 
inhospitable regions. Pringlea antiscorbutica differs from 
the normal type of the order Cruciferae, to which it belongs, in 
the entire absence of petals, the absence of honey-glands at the 
base of the flower, the long exserted style, and the stigma covered 
with long papillae — all pointing, as suggested by Dr. Hooker, to 
the conclusion that the Pringlea is an anemophilous species in 
an order usually entomophilous. This inference is in harmony 
with the fact of the almost entire absence of winged insects in 
that country, which is constantly swept by the most furious 
winds. It is true that Mr. Moseley, the naturalist to the 
Challenger expedition, reports having found numbers of an 
apterous fly crawling over the foliage of the plant ; but, 
singularly enough, he saw none on the inflorescence itself; 
whether they have any share in the fertilisation of the flower 
will remain for future explorers to discover. Having an 
opportunity of examining the pollen-grains under the micro- 
scope, I found them altogether in accordance with the 
hypothesis that the pollen is carried by the wind. While the 
usual form of the grains in Cruciferae is ellipsoidal and three- 
furrowed, as illustrated in Aubrietia (fig. 12), or in the more 
nearly allied Sisymbrium officinale (fig. 55), those of Pringlea 
are, as exhibited in fig. 56, very minute and perfectly smooth 
and spherical. 
Hermann Muller, who has devoted much attention to the 
reciprocal adaptations of flowers and insects to each others’ 
needs, has described in his “ Befruchtung der Blumen durch 
Insekten,” and in greater detail in 64 Nature ” (vol. viii. p. 433, 
et seq .), a remarkable kind of “ dimorphism ” exhibited by 
certain flowers. Our figs. 1 and 2 (Plate CXX.) are taken 
from the latter series of papers, and illustrate the phenomenon 
in the case of the common eye-bright, Euphrasia officinalis , so 
pretty an ornament to our hill-sides and heaths. If the 
specimens of this flower growing in different localities are 
observed, it will be found that those that inhabit more open 
sunny places have larger and more brightly-coloured flowers, 
while the flowers of those in more shady situations are smaller 
and paler — the relative sizes being represented by figs. 1 and 2 
(both considerably magnified) — and that this difference in size 
is accompanied by other structural differences which favour 
cross-fertilisation in the one, self-fertilisation in the other case. 
If a flower of the larger form which has just opened (fig. 1 a) 
is examined, the stigma, st , already in a receptive condition, 
considerably overtops the anthers, an. Each of the two lower 
