THE CHOICE AND QUALITY OF SEED. 21 



that after some years our flax and hemp seeds will be 

 transformed into dwarf species. 



" Colza, of the large kind, which we harvest before its 

 complete maturity, in order to avoid losing the seed, di- 

 minish in height after a few years. If afterwards we allow 

 these degenerated species to attain maturity, we shall restore 

 their size by degrees, until they reach the point from which 

 they had declined. We may therefore diminish or increase 

 in size the breeds of animals and species of plants, by em- 

 ploying for reproduction, individuals that have acquired all 

 these qualities, and are capable of transmitting them ; or 

 else, by taking others imperfect, and unable to impart what 

 they do not possess. 



"Twelve or fifteen years ago, trefoil sown in one of my 

 fields, after presenting in autumn the finest appearance, 

 disappeared in the spring. The leaves shrivelled up, the 

 stalks did not rise, the major part of the plants dried, and 

 were attacked with a species of decay. I attributed this 

 disease at first to the state of the soils, then to the tem- 

 perature ; in short, to three or four other causes more or 

 less likely ; but the bad quality of the seed did not occur 

 to my mind. 



" Some years later I harvested, before its full maturity, 

 some rye that T had sown for forage, and which, not being 

 able to consume it in proper time, was kept to make bands. 

 It was cut while yet green ; but the grain, in appearance 

 ripe, had probably not acquired that degree of perfection 

 indispensable for reproducing its species. I sowed this 

 rye in order to obtain forage in the spring. It came up 

 well, and exhibited a good vegetation at first ; then the 

 foliage became yellow and wasted, and the soil became so 

 denuded, that I found it necessary to plough it up to re- 

 place it with another crop. Many causes were alleged for 

 it, but the true one remained still unknown. Last year, 

 however, in a field of three hectares, which had borne a 

 fine crop of beetroot, I sowed in April barley and clover. 

 In two-thirds of the field I sowed clover-seed of middling 

 quality that had been taken from very vigorous plants, but 



