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subject with an ever-increasing literature, the stigma, and in receiving more pollen 



Every kind of flower has its own particu- for another flower. 



lar way of solving the problem, so that the One of the most remarkable cases of in- 

 subject will never be completed until all sect-pollination is that shown by the ordi- 

 flowers have been questioned and their nary Yucca, which is pollinated by a small 

 answers obtained. moth, the plant and the moth being very 

 Any account, however brief, should not dependent upon one another. The flow- 

 omit mention of the orchids, which in the ers of Yucca occur in very large prom- 

 matter of insect-pollination have reached inent clusters, and hang like bells. In 

 the highest degree of organization. So each bell-shaped flower there are six 

 detailed are their adaptations that each hanging stamens, and a central ovary 

 kind of flower is adapted to a particular ribbed lengthwise like a melon. At the 

 kind of insect. The accounts given of the tip of the ovary is a funnel-shaped open- 

 various ways in which orchids attract ing, which is the stigma. During the day 

 insects and secure pollination really sur- the moth hides quietly in the recesses of 

 pass belief, until one has actually ob- the flower, but at dusk she becomes very 

 served some of the plants and their in- active. She travels down the stamens, 

 sects at work. Any greenhouse furnishes and, resting on'the open anthers, scrapes 

 abundant examples of orchids, and our out the somewhat sticky pollen with her 

 illustration represents one of the most front legs. Holding the little mass of 

 common of our native orchids, the ordi- pollen she runs up on the ovary, stands 

 nary yellow Ladyslipper. In most orchid astride of one of the furrows, pierces 

 flowers there is a long tubular spur, at the through the wall with her ovipositor, and 

 bottom of which the nectar is found, deposits an egg in an ovule. After depos- 

 which is to be reached by long probosces, iting several eggs, she runs to the apex 

 such as can be found only in moths and of the ovary and begins to crowd the mass 

 butterflies. In Ladyslippers, however, of pollen she has collected into the funnel- 

 there is a different arrangement. The like stigma. These actions are repeated 

 flowers have a conspicuous pouch in several times, until many eggs are depos- 

 which the nectar is secreted, and a flap ited and repeated pollination has been 

 overhangs the opening of the pouch. Be- effected. As a result of all this, the flower 

 hind the flap are the two pollen masses, is pollinated and seeds are formed, which 

 between which is the stigmatic surface, develop abundant nourishment for the 

 A bee crowds itself away into the pouch moth ^rvae, whose eggs had been laid 

 and becomes imprisoned, and may fre- in . the ovule Just how the insect learned 

 quently be found buzzing about uneasily. that th i s ^fhavior on her part would se- 



The nectar is in the bottom of the pouch, cure - food for her ^ oun - 1S hard ta 



j e L f j- t t i imagine, 



and after feeding the bee moves toward In stud in flowef there ^ three 



the opening overhung by the flap, and questions that should be asked: (l) How 



rubs itself against the stigma and then does it hinder self-pollination?; (2) How 



against the anthers, receiving the pollen does it secure cross-pollination ? ; (3) How 



on its back. A visit to another flower will does it discourage the visits of unsuitable 



result in rubbing some of the pollen upon insects ? John Merle Coulter. 



