100 BOARD OF AGRICULTURE. 



many years before his works were published in this country. 

 Did time permit, we might cite from his writings numerous 

 references or quotations, which would furnish most striking 

 evidence in proof ^nd illustration of this law of propaga- 

 tion, as applied, not only to the human species, but also to 

 the domestic animals. 



VEGETABLE PHYSIOLOGY. 



In that part of Darwin's works treating of plants, we find 

 strong evidence that this same law prevails throughout the 

 vegetable kingdom. The same may be said also of other 

 writers on vegetable physiology. It is a fact well attested by 

 gardeners, that in order to produce flowers and fruit the soil 

 must not be too rich or too poor. If the plant or tree grows 

 too luxuriously, its branches or roots must be pruned ; while 

 on the other hand, if unthrifty, it must receive better culture 

 and its roots be enriched before it will become fruitful. So 

 the most beautiful flowers and richest fruits have few seeds, 

 which in time run out, while those of a poor quality may 

 abound in seed, but will not flourish long. It is true, the 

 conditions here vary, and so do the modes of perpetuating 

 life; but by analogy in a great variety of ways, we believe 

 that strong arguments may be deduced from the laws that 

 regulate the continuance, increase and decay of vegetable life, 

 to confirm the truth of the principles of propagation and in- 

 heritance as advocated in this paper. 



But some of the strongest evidence in proof of this law is 

 found in human physiology. It presents to man the highest 

 standard of health, of longevity, of happiness, of strength, of 

 beauty, etc. Proofs are derived in its favor from the laws and 

 changes of disease ; from the causes of fertility and sterility ; 

 from facts connected with insanity, idiocy and mutism ; from 

 the transmission of genius and other mental peculiarities ; 

 from changes in population, explaining why certain tribes and 

 races increase in numbers for generations, whilst others de- 

 cline ; why the highest and the lowest types of human organ- 

 ization, after a time, also decline; and that those having an 

 organization between the two extremes, are found best fitted 

 " to be fruitful, to multiply and replenish the earth." 



It may appear to some that the law of propagation as here 



