23 



with sufficiently large numbers to neutralise individuality and small 

 accidents, which sometimes produce most unaccountable variations. 



If we consider the bearing of all the data now brought forward, it 

 seems reasonable to assume that in the ultimate analysis we are deal- 

 ing with acquired and inherited tendencies. In the one case the im- 

 pulse or stimulus to development comes from without ; it is environ- 

 mental, and acts more strongly upon the somatogenic portion of the 

 plant, while in the otier case it is inherent in the organization of the 

 seed and derived from the parent plant. Whatever the explanation 

 of the origin maybe, however, it seems certain that these two opposing 

 factors of increase play an important role in the economy of nature. 

 As the food supply is lessened, a greater effort is made on the part of 

 the parent plant to enhance the chances for perpetuity ; but at the- 

 same time the largest seeds, having the greatest potentiality, stand 

 the best chance in the future struggle ; and although the best nou- 

 rished plants produce the fewest seeds, their greater size gives them 

 decided advantages over seeds from starved plants. The two laws 

 acting together Therefore, aid in maintaining the perpetuity of the 

 species and its full measure of vigour. 



TABLES. 



I. Yield of Wheat on Fertilised and Unfertilised Ground. 



(Weights caloulated to the acre ) 



Treatment. 



Weight of 

 straw in 

 pounds. 



Weight of 

 grain in 

 pounds. 



Proportion of 

 straw to 

 grain. 



Unfertilised 



2.813 



1,602 



1:0.56 



Commercial Fertiliser ... 



f 4,279 

 1 3,971 



1,938 

 1 884 



1:0.45 

 1:0.47 



Unfertilised 



2,727 



1,506 



1:0.55 



Stable Manure 



f 3,699 

 \ 3,361 



1.818 

 1,728 



1:0.49 

 1:0.51 



Unfertilised 



2,894 



1,512 



1:0.52 



Average unfertilised ... 



2,811 



1,540 



1:0.55 



Average fertilised 



8,880 



1,842 



1:0.48 



