134 On inuring Tender Plants to our CUmate. 



It is probable that wheat, our principal food at present, 

 did not bring its seed to perfection in this climate, till 

 hardened to it by repeated sowings : a few years ago some 

 spring wheat from Guzerat was sown with barley, in a well 

 cultivated field : it rose, eared, and blossomed, with a heal* 

 thy appearance; but many ears were when ripe wholly with- 

 ont corn, and few brought more than three or four grains 

 to perfection. 



In the year 1791, some seeds of zizania aquatica were 

 procured from Canada, and sown in a pond at Spring 

 Grove, near Hounslow: it grew, and produced strong plants, 

 which ripened their seeds: those seeds vegetated in the suc- 

 ceeding spring ; but the plants they produced were weak, 

 slender, not half so tall as those of the first generation, and 

 grew in the shallowest water only ; the seeds of these plants 

 produced others the next year sensibly stronger than their 

 parents of the second year. 



In this manner the plants proceeded, springing up every 

 year from the seeds of the preceding one, every year becom- 

 ing visibly stronger and larger, and rising from deeper parts 

 of the pond, till the last year, 1804, when several of the 

 plants were six feet in height, and the whole pond was in 

 every part covered with them as thick as wheat grows on a 

 •well managed field. 



Here we have an experiment which proves, that an an- 

 nual plant, scarce able to endure the ungenial summer of 

 England, has become, in fourteen generations, as strong and 

 as vigorous as our indigenous plants are, and as perfect in 

 all iis parts as in its native climate. 



Some of our most common flowering shrubs have been 

 long introduced into the gardens ; the bay-tree has been 

 cultivated more than two centuries; it is mentioned by Tus- 

 ser, in the list of garden plants inserted in his book, called 

 500 Points of good Husbandry, printed in 1573. 



The laurel was introduced by master Cole, a merchant, 

 living at Hampstead, some years before 1629, when Par- 

 kinson published his Paradisus Terres^tris, and at that time 

 we had in our garaens, oranges, myrtles of three sorts, 

 laurustinus, cypress, phillyrea, alaternus, arbutus j a cac- 

 tus 



