50 REPORT OF THE COMMISSIONER OF AGRICULTUliE. 



" In otlierf?, and in most fresh pollen, when placed in ordinary aerated 

 water, at least when this is slightly thickened by sirup or the lilic, and 

 submitted to a congenial temperature, a projection of the inner coal 

 through the outer appears at some point, and by a kind of germination 

 grows into a slender tube, which may even attain to three hundred 

 times the diameter of the grain, and the riclier protoplasuiic contents 

 tend to accumulate at the farther and somewhat enlarging extremity 

 of this pollen tube, 



" Commonly the pollen remains unaltered until it is placed upon the 

 stigma. The more or less viscid moisture of this incites a similar 

 growtli, and also doubtless nourishes it, and the protruding tube at oner, 

 I>enetrates the stigma, and by gliding between its loose cells buries it- 

 self in the tissue of the style, descending thence to the interior of the 

 ovary and at length to the ovules. Fertilization is accomplished by the 

 action of this pollen upon the ovule, and upon a special formation 

 within it. Consequent upon this an embryo is formed, and the ovule 

 now becomes a seed. 



" Hybridization at the present time is only done by fresh pollen — in 

 grains (cereals) and in potatoes. 



" Pollen contains much nitrogen and phosphorus, the two most precious 

 of all the elements for tlie growth of ])lant8, but in the case of most open 

 ilowers a large quantity of pollen is consumed by pollen-devouring in- 

 sects and a large quantity is destroyed during long-continued rains. In 

 order to compensate the loss of pollen in so many ways, the anthers 

 produce a far larger amount than is necessary for the fertilization of 

 the same flower." 



SAVING POLLEN. 



"The improvement of races of plants is not destined to stand still, more 

 than in the case of other improvements," says the Horticultural liovieir, 

 '•and nothing would tend more to the speedy termination of an experi- 

 ment than that we had control over the supply- of pollen, so that wc 

 might use it when and where convenient to ourselves. We have had 

 reports of failures in trying to keep a harvest pollen, from Australia, 

 India, ITorth America, nnd from many people in this country, but from 

 none of them have we lifeard one word about the process of ripening and 

 drying the pollen. Pollen fifty years old, in a herbarium, was found, 

 under a microscope, to yield to moisture exactly as fresh- gathered pol- 

 len would do, the little bags distending till they burst ; the matter dis- 

 charged differed in no way from that of a recent anther. 



" Failures in saving pollen arise from want of thought. If the anthers 

 become ripe or near to ripeness they will open during the process of 

 drying, and we might jiist as well attempt to lock up electricity as to 

 secure tlie ])ollen grain from destruction. All that we have actually 

 proved on the subject is this, that if we extract the anthers and stamens 

 long before the anthers are ripe, the pollen in them will ripen and be in 

 use and tit to cross after the lapse of six months, while pollen gathered 

 when rijie and flying out of the anthers, though kept with the greatest 

 care, would not fertilize the stigma of the iiarent plant at the end of a 

 month. 



" We believe the driest atmosphere we can keep in our rooms and 

 drawers is far too moist for the preservation of pollen for any length of 

 time after being actually exposed to it ; and we also believe that an 

 anther would keep as long as a bladder under the same influences, and 

 that it is as impervious to moisture as the bladder, and therefore as ca- 



