hy Lindlei/s Theory of Horticulture. 4'4f3 



the pollen, and the particles of farina will not divide so freely, 

 nor will they will burst so readily on the top of the stigma, in 

 cold wet weather. Most practical gardeners, however, are of 

 opinion, that fruit sets best in a moist heat : perhaps the moist 

 heat is favourable to the developement of the glutinous secretion 

 on the top of the stigma. In preserving seeds, keeping them 

 cool and dry is certainly the principal means to be used ; 

 exposure to either heat or moisture in excess must injure. The 

 great danger to seeds crossing the equator is heat ; and as sub- 

 stances that are slow in absorbing heat are equally slow in 

 radiating, and consequently retain heat, it may be difficult to 

 get a proper medium to exclude this danger. Charcoal has 

 been used, some say, because it is a bad conductor. Professor 

 Thomson says, charcoal prepared in the usual way, at a low 

 heat, is a good conductor ; and only when prepared at a red 

 heat, a bad conductor : the charcoal may, however, help to dry 

 up the moisture. Grey paper packets, and coarse canvass bags 

 with free ventilation, and the seeds dry, as observed by the 

 professor, form perhaps the best way of packing in seeds cross- 

 ing the equator. Berries are best packed among very dry sand, 

 to dry up the moisture as the pulp decays. Where excess of 

 heat and moisture can be guarded against, exclusion from air is 

 the greatest requisite : it is difficult to exclude it perfectly, but our 

 experience would lead us to infer that the more this is done, as 

 when kept in heaps, and enclosed in thick and double bags, the 

 better does the seed preserve its vitality. We have before taken 

 notice of the great loss of weight sometimes occurring in onion 

 and other waxy seeds : in clover seeds, the colour is the practical 

 test of its quality ; and in seeds of these kinds preserved from 

 air as much as possible, the clover has a better colour, the 

 onions, &c., are heavier, and grow better. When excluded 

 completely from air, by being very deeply buried, seeds will live 

 for indefinite periods ; as has been frequently experienced from 

 the plants springing out of earth dug from deep mines. Some 

 oily seeds, as turnip, &c., keep long. The Scotch fir, an oily 

 seed, will keep longer than spruce or larch, farinaceous seeds. 

 The coffee, a farinaceous seed, loses its vitality very soon. The 

 lint seed, again, an oily seed, will not keep so long as some 

 farinaceous seeds. The oak has a hard shell, and farinaceous 

 cotyledons, and yet will not keep so long as some seeds that are 

 much softer. Oily seeds are most easily hurt by excess of 

 moisture, and farinaceous seeds by heat ; but it is impossible to 

 give a general rule : the vital principle is most likely strongest 

 in those that keep longest. On the maturation of the fruit, the 

 remarks on the size of the fruit being at the expense of the seed 

 and high cultivation, consequently against the vigour of the 



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