BOTANY. 



307 



so as to render the result doubtful and wholly inefficient ; at others the 

 result has been unsatisfactory, because the most favorable moment for 

 the operation has been overlooked. A rainy or wet day, for instance, 

 always lessens the destructive efficacy, because the powder, containing 

 a very volatile essential oil, renders the conservation of this principle 

 extremely difficult. 



Of all the methods for applying the powder to plants attacked by in- 

 sects, including the vine, the bellows will best accomplish the object. 

 As there is only a small quantity of powder thrown at once, the loss 

 wilt be very small, whilst in any other way a good deal of it will fall 

 upon the ground. The powder should be directly applied to the parts 

 operated on, and with care and precaution it may be made to penetrate 

 into the most inaccessible parts of a plant. If, for instance, a plant has 

 been attacked by plant lice, which are often hidden or masked by 

 thick foliage, it will become necessary to turn aside this foliage, so as 

 to have the insects exposed, and the powder directly brought into con- 

 tact with them. In all cases these operations should take place on a 

 warm day, the morning being always preferable. A slight moisture 

 arising from the morning dew will make the powder more easily adhere 

 to the spots where it is applied, and maintain its properties long enough 

 to cause the death of the insects. The insufflation should be renewed 

 several times according to the nature and number of insects to be de- 

 stroyed. The first operation generally stupefies them, while at the 

 second or third application they lose their strength, fall to the ground, 

 and die sooner or later. 



M. Willemot also states, that by mixing the Pyrethrum powder with 

 wheat, in the proportion of two ounces to two or three bushels previous 

 to sowing the grain, the ravages of the wheat-midge may be entirely 

 prevented. 



IMPROVEMENT OF WHEAT. 



Mr. Hallett, an English agriculturist, has recently published the re- 

 sult of some interesting experiments on the improvement of the wheat 

 plant, whereby he has obtained a superior wheat, both in productive- 

 ness and weight. He commenced experimenting with what is known 

 in England as " nursery wheat," and details the course pursued as 

 follows : 



" A grain produces a stool, consisting of many ears. I plant the 

 grains from these ears in such a manner that each ear occupies a row 

 by itself, each of its grains occupying a hole in this row ; the holes being 

 twelve inches apart every way. At harvest, after the most careful 

 study and comparison of the stool from all these grains, I select the 

 finest one, which I accept as a proof that its parent grain was the best 

 of all, under the peculiar circumstances of the season. 



" This process is repeated annually, starting every year with the 

 proved best grain, although the verification of this superiority is not 

 obtained until the following harvest." The following table gives the 

 result at the end of the fifth year from the original sowing : 



Year. 



1857, Original ear .... 



1858, Finest ear .... 



1859, Ditto 



1860, Ears imperfect from wet season 



1861, Finest ear .... 



Length ill 



Inches. 



43-8 



61-4 



73-4 



83-4 



No. Grains. 



45 

 79 

 91 



123 



Number of 

 ears on Stool. 



10 



22 

 39 

 52 



