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How confidently would the superficial-nay, even careful-examination of one of the old-time botanists have interpreted its structure: "How simple and perfect the structure! Observe how the anthers are placed so that pollen shall naturally fall directly on the stigmas and fertilize them!" Such would indeed appear to be intended, until it is actually discovered that the stigmas have withered when the pollen is shed-a device which, acting in association with the little ring of hairs, tells a strange story. It is not my fortune to have seen one of these singular blossoms, but from the description of the process of fertilization given in Hermann Müller's wonderful work, aided by a botanical illustration of the structure of the flower, I am readily enabled to picture the progressive stages of the mechanism.

[Illustration: Fig. 13]

In the first stage (B, Fig. 13) small flies with bodies dusted with pollen from a previous arum blossom (for insects, as a rule, remain faithful or partial to one species of flowers while it is in bloom) are entering the narrowed tube, easily passing through the drooping fringe of hairs. Nectar is secreted by the stigmas, and here the flies assemble, thus dusting them with pollen. Their appetite temporarily satisfied, the insects seek escape, but find their exit effectually barred by the intruding fringe of hairs (C). In this second stage the stigmas, having now been fertilized, have withered, at the same time exuding a fresh supply of nectar, which again attracts the flies, whereupon, as shown at D, the anthers open and discharge their pollen upon the insects. In the fourth stage (E), all the functions of the flower having now been fulfilled, the fringe of hairs withers, and the imprisoned pollen-laden flies are permitted to escape to another flower, where the beautiful scheme is again enacted.

In a paper of this kind it is of course possible only to hint at a few representative examples of floral mechanisms, but these would be indeed incomplete without a closing reference to that wonderful tribe of flowers with which the theory of cross-fertilization will ever be memorably associated. I have previously alluded to the absolute dependence of the red clover upon the bumblebee. This instance may be considered somewhat exceptional, though numerous parallel cases are known. Among ordinary flowers this intervention of the insect is largely a preferable intention, and though almost invariably fulfilled, a large proportion of flowers still retain, as a dernier ressort, the power of at least partial self-fertilization and perpetuity in the absence or neglect of their insect counterpart.

[Illustration: Fig. 14]

The numerous and conclusive demonstrations of Darwin, however, have proved that in the competition for existence such self-fertilized offspring quickly yield before the progeny of cross-fertilization.