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POPULAR SCIENCE REVIEW. 
about simply by the descent of the carina, the reproductive 
organs themselves being entirely passive. As these have no 
tendency to spring upwards, there is no occasion for the upper 
edges of the carina to be united together. Such an arrange- 
ment would indeed interfere with easy depression. The edges, 
therefore, are either left ununited in their whole length, in 
which case the descent of the carina leaves the stamens and 
pistil fully exposed ; or they are united for some distance, but 
a fissure is left between them at the distal end, through which 
pollen and stigma protrude during the depression. What the 
special objects of these variations may be I do not profess to 
know. The same general purposes are, however, plainly dis- 
cernible in each case. These are — the protection of the repro- 
ductive organs at ordinary times from wind, rain, cold, and 
other noxious influences, and their exposure, at the moment of a 
bee’s visit, in such a way as to ensure their contact with its body. 
In the generality of Papilionaceous flowers it is the under side 
of the bee which is struck by the anthers. A striking excep- 
tion is furnished by the French Bean ( Phciseolus comm.) and 
the Scarlet Runner (Phas. coccineus) (fig. 4). The carina in these 
flowers is closed, excepting at the very end where the stigma 
projects very slightly from a round opening. It is adherent 
to the alse, not merely jointed with them. Instead of lying 
between them in a more or less horizontal position, it rises up 
vertically, and is coiled into a spiral form. This spiral is such 
that the opening at its end lies just above the only passage by 
which access can be had to the nectary. On looking at a flower 
in front (fig. 4), one sees this passage on one’s left ; and one 
sees that there is no open passage on the right, the carina being 
so placed as to block it up. A bee, then, in order to get at the 
nectar, must push its head and thorax directly underneath the 
opening from which the tip of the stigma is protruding (fig. 5). 
While doing this its weight acts through the alae, on which it 
stands, upon the adherent carina, which it depresses. The 
terminal opening is thus brought close to the bee, while the 
carina is stripped from the style — on which the weight does not 
act — and leaves a considerable length of this with the stigma 
uncovered, and in contact with the back of the bee. Judging 
merely by the length of the stamens, one would expect that the 
same movement which exposes the style would also expose the 
anthers, for these lie round the style only just behind the 
stigma, that is, round a part which the movement does lay 
bare. But the style is stout and resisting, whereas the fila- 
ments are slender and limp, and not firm enough to resist the 
friction of the retiring carina, with which they are therefore 
drawn back. The anthers, as they retreat, are of course rubbed 
against the stationary style. This is set with dense hairs, point- 
