8 THE PLANT. 



lose again some one or other of its distinguishing charac- 

 teristics. 



The influence exerted by the condition of the soil in 

 producing varieties of plants is observed most frequently 

 with seeds that pass undigested through the intestinal 

 canal of animals which have eaten them, and then receive 

 a different manurino;, accordino; to the various nature of 

 the excrements of divers animals with which they are 

 returned to the soil : an instance is afforded by the 

 Byrsonima verhascifolia (v. Martins). 



In the selection of seeds for planting, it is always 

 important to take into account the soil and climate from 

 which they have been derived. In England seed-wheat 

 from a poor soil is considered particularly well suited to a 

 rich soil ; rape-seed grown in colder regions or situations 

 is sure to give a good crop in warmer locahties. Clover 

 seed and oats from mountainous districts are preferred to 

 the same seeds from plains. Wheat from Odessa and 

 from South Hungary is esteemed in colder regions also. 

 The planters on the Upper Ehine import their hemp -seed 

 from Bologna and Ferrara. 



In hke manner many German flax-growers, who wish 

 to produce tall plants of uniform size, attach particular 

 value to hnseed from Courland and Livonia, where the 

 soil and the nature of the climate, especially the short 

 hot summer, bring the flowering and fruit time near 

 together ; so that the flowers, being simultaneously and 

 uniformly fiaictified, produce ripe and perfect seeds. 



Everyone knows how much the weather, during the 

 flowering period, influences the formation of seed. If, 

 after the flowering has commenced, cold weather or rain 

 sets in, retarding the full developement of the inflorescence, 

 the flowers fertihsed at a later period produce no seeds, 

 as the nutriment needed by them is apphed by the 



