Plant Physiology, Theoretic and Applied. 337 



clovers and pine-nuts germinate well after the lapse of ten years. Nay, on the 

 continent many gardeners contend that old seeds of many of the melon family 

 are best, in that the plants do not run so much to vine and leaf as do those 

 from fresh seed. 



Two mistakes which are often made in keeping over seeds through winter 

 are to subject them to too much heat or too much moisture or both. You often 

 hear it said, "I have my seeds in a good warm place and they will keep well." 

 This is just where they shouldn't be, for fully matured seed is not so lifeless 

 as we commonly imagine. 



It is constantly giving off slight quantities of water and carbonic acid even 

 when kept dry amd cool, and these quantities may be so increased by warmth 

 and moisture that fermentation and ensuing rotting may occur. If a dry, cool 

 place is not at hand in which to store our seed, not much danger is run in having 

 a moist locality, providing the temperature can be kept at about the freezing 

 point during the whole of the dormant season. Many seeds, as we all know, 

 such as nuts, grow best the next season if they have been "stratified" during 

 the winter. This consists in placing them in layers with moist sand between 

 the layers, and storing them in cool cellars or even out of doors. In this way 

 the hard coat becomes taore pervious to water, and germination the ensuing 

 spring is more rapid and uniform, if it has not already commenced. 



The second stage of germination, the softening or solution of the food 

 materials stored in the endosperm or cotyledons, requires not alone, as many 

 think plenty of water, but plenty of oxygen also. It is only by the presence 

 of much oxygen that those vital processes can go on within the seed, accom- 

 panied by the liberation of carbonic acid and the rise in temperature. For 

 this season seed should never be planted in soil saturated with water on the 

 one hand, nor in such stiff clay on the other that heavy showers followed by 

 hot weather will cause the soil to "bake." Either of these extremes can be 

 alleviated, if they cannot be avoided, by mixing much manure or even straw 

 with the soil when it is plowed. Plenty of oxygen means life to the plant 

 when germinating, but even a slight amount of carbonic acid retained about 

 the seed means death. A great difference exists also between seeds of differnt 

 plants which have swelled up, and which have either not germinated, or even 

 have, when subjected to alterations of drying and moistening ; and this dif- 

 ference manifests Itself rather remarkably in the two great classes of mono- 

 cotyledons, or seeds with one cotyledon, such as wheat, oats and barley, and the 

 dicotyledons, or seeds with two cotyledons, such as beans, peas and squashes. 

 While the seeds of the first will stand many alterations of drought and moisture 

 ■ — nay, will even grow if germination in a more advanced stage has been 

 stopped several times — the seeds of the latter nearly always succumb. The 

 first have the power of cutting off the dead and decaying portion of the rootlet 

 by a searing process and the formation of new ones above the place of decay ; 

 while with the latter, even if they continue for a time to grow, the poisons 

 from the dead or dying tissue ascend the roots, and the death of the whole 

 plant results. So, with your grains, such as wheat and rye, especially, you need 

 not fear if a drying process has followed a soaking, unless too long continued : 

 but if the field be clover, beets, turnips, or other dicotyledon, do not accept 

 the uncertainty, unless the season be too advanced, but sow again. 



Under the third stage of germination the expansion of the embryo, it may 

 be merely remarked in passing that the manager of a hot-house, or one who is 

 planting seed which he intends to water, must here be careful. It has been 

 proved beyond a doubt that if a plant at this early stage has too much water 

 or even only enough to force strong growth, it will demand that surplusage all 

 of its life. Cut down the supply to what would be enough for a plant left to 

 its own resources, or for one which had been artificially but properly supplied 

 with water, and our over-fed and pampered plant will grow yellow, weaker, and 

 perhaps die. Better too little water than too much, even if the plant wilt and 



HOR. 22 



