Epidemics. 259 



least; for the road, the chase, and the cavalry the improve- 

 ment has been considerable ; but for the race, saving where 

 feeding, stabling, and management are concerned, but 

 very little has been done, though the old stock of the 

 eighteenth century is not perfectly adapted for the present 

 century, and crossing would probably change the qualities 

 of the racer much, and make him, with our recent Royal 

 Turkish stud, a hardier, stronger, and more enduring 

 animal than he at present is, but probably not a fleeter or 

 larger horse. These latter qualities, no doubt, are greatly 

 the result of food, air, warmth, and well-regulated exercise, 

 with abundance of ease during the breeding period. The 

 amount of rest and gentle open air exercise, without too 

 rich feeding in the time of breeding, is essential in improving 

 the breed of cattle and horses. 



It is too much to enter at length into any floral products, 

 the decay of old kinds of plants and shrubs, and the adopting 

 of new and varied kinds of the same species. The same 

 may be said of crossing and improving our poultry and 

 aviary generally. Nor yet is it quite the thing to examine 

 our forest trees, as the oak, the beech, the elm, etc., etc. 

 These, of all other things, with our higher mammalia, in 

 their native wild state, suffer the least by epidemic changes 

 within the memory of man ; but yet it is not quite clear 

 whether the oak is not rather on the decline in its toughness 

 and growth, and the beech improved in both respects, during 

 the last fifty years, in this country and Europe generally. 



But questions of so great importance and so difficult of 

 solution require observations and comparisons beyond the 

 reach of most men to give, before anything can be decided 

 worthy of much attention. 



After these general observations, further inquiry into the 

 subject of transition or metamorphosis, so far as regards vital 

 phenomena, will be declined, feeling assured that in about 



172 



