303 BOTANICAL GAZETTE. 



organs of the flower; the corolla is deeply imbricated, find covers the stamens 

 and pistil. 



The anthers ot the young flower are very large and of a bright yellow; 

 they are composed of two mealy sacks which are slightly attached toirether 

 and fall back and nearly cover (he filament. 



As the flower grows and becomes larger, the anthers become smaller until 

 they are only about one-third of their original size. 



In the bud the pistil is already quite tall and has to take a stooping posi- 

 tion, but when the flower grows and opens the pistil takes an upright position 

 and always keeps above and out of the reach of the stamens. 



Most flowers require crossing, and the arrangement of most of them is 

 such as to prevent self-fertilization and to insure crossing. 



The above example is the most common mode by which self-fertilization 

 is prevented, but this plant has other and more striking illustrations of this 

 fact. 



The stigma is two-lobed and is so sensitive that if anj thing touches it, it 

 immediately closes, hence, when the Humming bird, the principal means by 

 which this plant is fertilized, hovers over the flower and sticks its long pro- 

 boscis down into the tube its head touches these lobes and they close almost 

 immediately and remain so for a short time. 



The anther cells are now open and ready to shed pollen, and as the bird 

 jiuts its head farther down into the tube, it hits these cells and the pollen is 

 dusted upon it, and flying back it hits the pistil again but the stigma is closed 

 and none of the pollen can get in. 



Bit when it goes into the next flower the stigma is open and the pollen is 

 shed upon its lips, sometimes so much as to be plainly seen by the naked eye. 



This process is repeated till the bird, tired ot the meagre amount of honey 

 it gets for is labors, flies to some other plant hoping for better success. 



Tills plant has an enemy in the black ant whicii does not enter the flower 

 at the mouth, but eats through the calyx and corolla and sucks the honey whicli 

 is laid up for the attraction of the birds. Even if the ant did enter at "the top 

 and get pollen upon it, it would immediately fall ofl' fnmi its smooth body 

 and l<\gs and thus use up the pollen which would be ot no use to the plant in 

 its fertilization. 



But the plant's bright and gaudy corolla attracts the birds and even if one 

 does not enter more than two or three flowers, yet it enters enough to scatter 

 tlie pollen on some pistil and fertilize it. 



It has often seemed to me that scientific magazines did not ])ay 

 enough attention to the best modes of teaching science. 



Prof. W. J- Beal, 

 Agricultural College, Lansing, Midi. 



Quercns lieterophylla, Michx.— This tree which for so many 

 years was comparatively unknown, now has its history very well writ- 

 ten, yet the number of trees known are very few, and their scarcity 

 has prevented the examination of the wood heretofore, perhaps entire 

 ly. The appointment of Prof. Sargent on the department of Forestry 

 in the Census Bureau, has led to the examination of all the species of 

 forest trees in the United States that could be procured. For this 

 purpose I secured a tree of this species, found growing near Mount 

 Holly, Burlington Co., New Jersey, and forwarded to him =;uch por- 

 tions as he desired ; there yet remain in my possession several sec- 

 tions, which I have thought might be desirable for museums and pri- 

 vate collections, where specimens ot our native woods are kept. I 

 will forward to each as may apply a specimen of this Bartram Oak 

 upon being informed of the dimensions desired. — Isaac C. Martin- 

 dale, Camden, N. J. 



