150 



THE GARDENER'S MONTHLY 



[ May, 



thcra serrata, which oi>en about noon and die in 

 a few hours, seed when I was ahnost sure no in- 

 sects had visited tlieni. In watchinc: for this 

 purpose Talinuni teretifoHuin, I found that it 

 opened always a few minutes before 1 p. m., l)e- 

 gan closing at three, and by half-past three had 

 wholly closed. No insect visited them in that 

 time, but every flower seeded, as did subsequent 

 experiments with single flowers. An ally, the 

 common Purslane, remains expanded only 

 from 8 to 9 A. m., and is, I think, an un- 

 doubted self-fertilizer, and yet on what theory of 

 the advantages of cross-fertilization could a plant 

 make better headway through the world? 



It is of course well-known that some flowers 

 are opening and closing at almost all hours of 

 the day and night, many remaining open but a 

 very short time. Can this varying and limited 

 time have anything to do with insect fertiliza- 

 tion ? Would not fertilization by insect aid be 

 more certain if at least a whole day were given 

 for the chance? In my district the little florets 

 of the Chicory are all fertilized before 8 o'clock, 

 and by nine have faded away. This species is an 

 excellent one for noting how self-fertilization is 

 eff'ected in composite plants, as the pistils are 

 blue and the pure white pollen is easily seen. 

 Soon after daylight, the corolla lengthens. After 

 a little while it rests, but the stamens and pistil 

 go on. Then the stamens cease to grow; 

 but the pistil continues to lengthen, carrying 

 an immense quantity of pollen with it. Here 

 is the difliculty which those who difler from 

 me experience. The pistil has to cleave, and 

 only on the interior of the clefts seeins to be the 

 stigmatic surface ; the pollen then must — it is said, 

 — rest of necessity only on the exterior, where 

 it cannot operate. But if any one will get up 

 early and spend a couple of hours in watching 

 the development of the flower, driving away an 

 occasional sand wasp that would like to gather 

 the pollen, he will find there is not a cloven pis- 

 til that has not some pollen on the interior stig- 

 matic surfaces. Of what avail are "must he's" 

 against positive facts like these ? But if he watch 

 closely he will see that this pollen fiills into the 

 chasm made by the opening stigmas. In the 

 language of my friends, it is a "beautiful ar- 

 rangement" for ensuring self-fertilization. If 

 further, we allow the sand wasps to work at pol- 

 len gathering, we find that while clearing the 

 pistils of pollen, they push quantities into the 

 clefts, and are, therefore, agents in self-fertiliza- 

 tion, instead of the reverse. I have observed the 



same in Dandelion and the Ox-eye Daisy, Chrys- 

 anthemum leueanthemum, as well as I am sure 

 that thousands flower and i)erfect seeds that no 

 insect visits. Tliere seems to be something yet 

 inexplicable as to how some flowers become fer- 

 tilized. In Cirsium (C. Pitcheri) and many others 

 of that section, what in others is a bifid stigma, 

 is nearly entire, the stigmatic surfaces being 

 almost, or perhaps in some cases wholly united 

 together. Cirsium Pitcheri has very long pistils. 

 The honey bee seems very fond of the flowers. 

 It works between the pistils. I have never de- 

 tected a grain of pollen on the almost entire 

 apex, though the sides are covered as in other 

 composites. But it seeds abundantly. 



I think the peculiar closings of flowers are as 

 much designs for effecting self-fertilization, as 

 for anything else. It does effect it in Ranuncu- 

 lus, Claytonia, and most likely in the Iris en- 

 closed in the gauze bag, and perhaps in many 

 I)lants with flowers that close and twist up in 

 fading. In Ranunculus, on the first day's open- 

 ing of the flower, the outer of the numerous rows 

 of pistils throw their pollen on the glazed petals. 

 These close at night, and the pollen is dropped 

 in over the hollow in which are the mass of per- 

 fect pistils. I refer to R. bulbosus. In Claytonia 

 (C. Virginica) the same thing occurs with the 

 early flowers, so far as drawing the stamens up 

 to the pistils is concerned. In the later flowers 

 the anthers recurve more, and in the closing at 

 night are drawn under the pistils, and hence we 

 find seed here only from the earliest flowers. 

 These illustrations are not uncommon. Even in 

 wind fertilizing flowers the times of opening and 

 closing of certain parts of the flowers, maybe 

 worth a study. I find Luzula campestris — the 

 wood form — bursts its anthers about o'clock 

 A. M. By ten, the pollen is committed to the 

 atmosphere. As its own pistil has dried up by 

 this time, having expanded two days before, it 

 cannot fertilize its own pistil. There is no evi- 

 dence that it would not be just as well if it could. 

 This precision and uniformity as to time, shows 

 that there are other considerations involved in 

 the acts connected with fertilization, besides 

 those usually suspected. 



(To be continued.) 



EDITORIAL NOTES. 



Nymph^a lutea. — The yellow water lily that 

 figured in Audul)on, has been re-discovered in 

 Florida, by Mrs. Mary Treat. 



