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vated pumpkins and squashes. He has arrived at the conclusion, 

 that nearly all those grown in our gardens may be referred to 

 one single species. He has particularly examined the changes 

 which artificial impregnations will produce. We often hear that 

 cucurbitaceous plants should not be grown together, or they will 

 injure each other. This gives rise to the question, whether the 

 fruit of the same season can acquire another's peculiarities without 

 first being grown from the seed, the result of such impregnation. 

 Such has proved to be the case. The influence of the pollen on 

 the fruit of the same year is such as to communicate to it the 

 characteristics of the plant furnishing the pollen. But M, Nau- 

 din finds that true species, undoubtedly distinct, can scarce be 

 made to hybridize, and that extensive and ready hybridation 

 takes place only among varieties of one species. Dr. Gray has 

 shown me recently an ear of corn exhibiting a hybridation more 

 or less common. It was sweet corn, in which kernels of hard, 

 smooth, yellow corn were irregularly distributed, contrasting with 

 the white, wrinkled kernels of the sweet. Here the mere im- 

 pregnation of the germ of white corn by the pollen of the yellow 

 had been sufficient to convert those grains which it touched into 

 perfect yellow corn. 



The spoi'ts and varieties of corn have a strong bearing upon 

 the question of the specific identity of these varieties of Sorghum. 

 Though some botanists have made species out of the varieties of 

 Indian corn, it is generally believed that these are all the results 

 of cultivation on one species. One peculiarity of one form claims 

 attention here. The plant has been found growing, apparently 

 wild, with the grain entirely covered by the glumes, which pro- 

 ject far beyond it. But it is said, that, after a little cultivation, 

 these glumes disappear, or become so abbreviated as to allow the 

 grain to be entirely uncovered, as in our garden growths. This 

 same difference is to be seen in the varieties of Sorghum under 

 consideration. The Dourrha most exhibits this abbreviation of 

 glume and prominence of grain, and this variety is that which is 

 known to have been longest under cultivation. 



The question, then, arises, whether plants would so freely hy- 

 bridize and exchange peculiarities, were they of different species. 

 Does not this hybridity point to identity ? We do not see other 

 grasses, which grow broadcast in our fields, hybridizing naturally, 



