CHAPTER ON SEEDS. 



class ; for while the Indian Mallow (Ahutilon avicennce) will not germinate unless 

 accompanied by a heat of over G0°, the garden Speedwells (Feroneca arvensis, V. 

 Buxbaumii, V. serphyllcefolia, &c.,) will readily appear through the soil with the 

 heat anywhere above 32°. 



A knowledge of the separate requirements of each seed constitutes practical talent, 

 and this can not be acquired without extensive experience and observation ; but, a few 

 principles can be derived from these, which will do much to simplify the labors of 

 those who have to go over the same ground. 



I have said that heat and moisture act mechanically in the process of germination, 

 — and they do so in this manner: On the application of heat, the pores of the skin 

 are expanded in the outer case or husk of the seed ; into these pores moisture is 

 admitted ; and then commences the chemical action which is to effect its germination. 

 An element of the water, which chemists call oxygen, seizes on one of the elements of 

 the husk, carbon, the charcoal principle, and forms a new combination, and disappears 

 in the shape of a gas, carbonic acid, one of the chief sources of food for the young 

 plant as soon as it shall have produced perfect leaves. As soon as this combined 

 force has eaten its way through the husk, it has to perform a similar duty for the 

 "kernel" inside. When this portion of the seed has been in like manner operated 

 upon, it receives its commission to go forth, increase, and multiply, and in short take 

 upon itself all the duties and responsibilities of a living plant. 



" But you have said nothing about air. Heat, air, and moisture, are frequently 

 written of in treatises on germination. What office does air hold in the process ?" 

 None whatever, my good friend. Air is a positive injury in the case, though of 

 immediate importance directly after the pushing of the embryo. Air, in conjunction 

 with light, hardens the outer coat — chemically speaking, fixes the carbon — which it 

 is the object of germination to destroy. I have no doubt seeds would " swell " in 

 distilled water, though I can think of no direct experiment of the kind just now ; but 

 even water plants must send their true leaves to the surface in search of air, immedi- 

 ately after germination. 



All these principles teach us that in preserving the vitality of seeds, or in accelera- 

 ting their germination, a great part of our attention has to be directed to their outer 

 coverin'gs. Seeds can not lose their vitality while these remain perfect, while they 

 will be in a condition to vegetate whenever this covering is prepared to admit mois- 

 ture. The different results in the experience of different parties in the time required 

 by certain seeds to grow, is entirely dependent on this. If A preserves his seed 

 during the winter so that the husk becomes hard and bony, while B guards his from 

 such a contingency, the latter will arrive at much more speedy results than the former. 

 Let us take an example : the Sugar Maple will do. A gathers his at the fall of the 

 leaf, preserves it in a dry seed-room, sows it in the spring, and — it does not come up 

 till twelve months afterwards. But B gathers it at the same time, puts it in the 

 ground at once, and gets fine plants the next season ; or, he gathers his seeds by the 

 end of August, saves them in a cool room till spring, sows them, and then gets 

 also " right away," in either case getting ahead of his neighbor. "But where 



