SEED-SOWING. 29 



1 12 for Cress, Pumpkins, and Maize; nofor Beans; 104 

 for Broad Beans, Wheat, and Barley; and 100 for Peas. In 

 such annual plants, the nearer the temperature approaches the 

 maximum the sooner will the seeds germinate : for instance, 

 Maize germinates in thirty to thirty-five days, in a temperature 

 of from 45 to 56; in twenty to thirty days, 67 to 75; in 

 seven to eight days, 90 to 100; Barley in forty to forty-five 

 days, in a temperature of from 35 to 45; in twenty to twenty- 

 five days, 55 to 60; in ten to twelve days, 94 to 100. For 

 tropical seeds we have named a temperature of from 70 to 90, 

 but there are some seeds which require a still greater heat to 

 cause them to germinate ; for instance, the seeds of the gigantic 

 Water-rose of the Amazon river require a heat of from 95 to 

 105 before they will germinate. 



If seeds are to be sown as soon as they are gathered, it is 

 as well to observe that the germ or embryo of the seed is fully 

 capable of perfect germination long before the seed has arrived 

 at that perfect state of ripeness or maturity which is necessary 

 to insure its keeping properties ; and if seeds are gathered at 

 the first stage, or sown as soon as the embryo is perfect, they 

 germinate much quicker than when perfectly ripe. We see 

 illustrations of this fact in wet seasons, when the seed of cereals 

 frequently germinates in the ear. The reason that young 

 seeds, or seeds sown directly they arrive at that stage of per- 

 fection when healthy germination is possible, grow more 

 quickly, is because they contain less carbon than those perfectly 

 hardened and dry ; for the more carbon a seed contains, other 

 things being equal, the longer that seed is in germinating, 

 because it must get rid of a large proportion of that stored-up 

 carbon ere it will grow ; or, in other words, after nature has 

 stored it with sufficient carbon to insure its keeping power 

 for one or more years, certain important chemical changes 

 must take place before it can develop leaves and roots. 

 Naturally, when a seed falls or is sown in moist earth, it 

 absorbs water from the soil, and also decomposes it, if the seed 

 is in a healthy state ; but if the seed is unhealthy, its tissues, 

 instead of separating oxygen from the water, and thus getting 

 rid of the superfluous carbon in the form of carbonic acid gas, 

 become clogged with superfluous moisture, and rot. Moisture, 

 then, is one of the greatest aids to germination, but the amount 

 of moisture essential is a most important point. Strong-growing, 

 healthy seeds may be placed in a shallow vessel and covered 

 with water until germination takes place, when they may either 

 be potted or planted out in the soil ; but, on the other hand, 



