1811.] 



AND HORTICULTURIST. 



149 



the feeding roots are near the surface, and 

 when this is the case the wood-growth is always 

 healthy, ripening thoroughly. Even those who 

 "scarify" the orchard surface, always contend 

 that they must leave off early in Summer, or the 

 wood "does not ripen well," and injury follows. 

 Then you can never injure such trees by over 

 manuring ; you may make a manure pile around 

 a tree whose roots are on the surface, and it will 

 rather rejoice than pout at your treatment. The 

 trees do not suffer from heated soil in Summer, 

 as under grass the earth temperature seldom 

 rises to more than 85° in the hottest weather. 



Now you see these reasons will vary in differ- 

 ent places. In sandy soils the feeding roots run 

 deeper, and hence " cultivating," as our friends 

 of the hoe-harrow call it, is not so injurious. In 

 the North the hottest Summer sun would not 

 raise the earth temperature over 85°, and there 



would not be the same need of screen from the 

 sun, but then grass keeps the frost from entering 

 the ground deeply, and in the North that will be 

 a blessing. Then some people settle in poor, 

 very poor places, where manure is not to be had 

 for love nor money, and then it is far better to 

 keep down grass with all its advantages, than to 

 have grass and trees both starving together. 



So you see there is no " grass system." We 

 cannot tell anybody whether he ought to have 

 grass in his orchard or clean culture, unless we saw 

 it. All we say is that in regular farming regions, 

 where people have the ordinary farming conve- 

 niences, and where the ordinary farming routine 

 can cover the orchard as well as any other part 

 of the farm, more money can be made from a 

 well-managed orchard in grass, than from an or- 

 chard managed in any other way. It is the cheap- 

 est and best of all orchard practices. — Ed. G. M.] 



Matur 



ISTORY AND fSClENCE. 



ON SELF-FERTILIZATION AND CROSS-FER- 

 TILIZATION OF FLOWERS. 



BY THOMAS MEEHAK, GERMANTOWN, PHILA. 

 (Continued from page 118.) 



The chief arguments for the necessity for in- 

 sect fertilization are drawn from structure, and 

 not from fact. For instance, we are told that 

 Iris, Campanula, Dandelion, Ox-eye Daisy, the 

 Garden Pea, Lobelia, Clover, and many others, 

 are so arranged that they cannot fertilize them- 

 selves without insect aid. I have enclosed flow- 

 ers of all these named, in fine gauze bags, and 

 they produced seeds just as well as those ex- 

 posed. I was somewhat surprised at the two 

 first, Iris Virginica and Campanula, producing 

 seeds under these circumstances, as they are 

 common illustrations of the necessity of insect 

 fertilization. In short, in all the cases I have 

 tested in this way, seeds were produced as well 

 under the gauze as without, except in one in- 

 stance — Baptisia australis. In most Papiliona- 

 ceous plants that I examined, in spite of the 

 suggestions of my friends, I thought the arrange- 

 ments favored self-fertilization ; not only by the 

 position of the organs, but from the fact that the 

 moment anything touched the flower so as to 



liberate the pistil or stamens, a cloud of pollen 

 floated all around like a little cloud; a disper- 

 sion of pollen, which, by the way, in view of pre- 

 vailing theories, the class of flowers with " fra- 

 grance, color, or honeyed secretions," ought not 

 to make. Genista scoparia will give an excellent 

 illustration of this. But in Baptisia I did not 

 notice this little cloud ; and it did seem in the 

 actual act of collecting honey, the humble bee's 

 pollen covered abdomen pressed itself closely 

 down on the stigma. I covered a spike of a 

 dozen unopened flowers with a gauze bag, and 

 had only one seed vessel, though in the exposed 

 spikes nearly every one perfected. This fact may 

 go for what it is worth; for be it remembered, lam 

 far from denying that flowers are sometimes ferti- 

 lized by the aid of insects. It is the extent of these 

 facts, and the theories to be deduced from them, 

 that I have to deal. Independently of trials by 

 gauze bags I have experimented with single 

 flowers of some species. I take plants of which 

 there are no others in the vicinity, and pick off 

 all but a solitaiy flower, not permitting another 

 to open until the other has faded, and if they 

 seed, it must be only by own pollen. I was led 

 to trv this from noting a few first flowers of (Eno- 



