ROS 



522 



ROT 



and by layers, is the only mode of pro- derive different materials from tlie soil ; 

 pagating the gold and silver-striped and though the vegetables having the 

 varieties. Sow in March or early in i smallest systems of leaves, will propor- 

 April, in drills one inch deep and six tionately most exhaust the soil of corn- 

 inches apart. The rooted slips, and 

 the cuttings of the young shoots, must 

 be from five to seven inches long, and 

 planted in a shady border, in rows 

 eight or ten inches apart. Previously 

 to being inserted, remove the leaves 

 from the lower two-thirds of their 

 length. Layers may be formed by cut- 

 ting young branches half through on 

 their under side, and pegging them 



mon nutritive matter, yet particular 

 vegetables, when their produce is car- 

 ried off, will require peculiar principles 

 to be supplied to the land in which 

 they grow. Strawberries and potatoes 

 at first produce luxuriantly in virgin 

 mould recently turned up from pasture, 

 but in a few years they degenerate and 

 require a fresh soil; and the organiza- 

 tion of these plants is such as to be 

 down an inch or two below the sur- ! constantly producing the migration of 

 face ; they become established plants their layers. Thus the strawberry by 

 by autumn. Water must be applied its long shoots is continually endea- 

 abundantly at the time of planting, vouring to occupy a new soil ; and the 

 and occasionally afterwards until es- fibrous radicles of the potato produce 



tablished. 



bulbs at a considerable distance from 



The plants require no further care the parent plant. The most remarkable 

 than to be kept clear from weeds, and instance of the powers of the plant to 

 in September to be transplanted to re- ; exhaust the soil of certain principles 

 main, being performed, in preference, necessary to its growth, is found in 

 during mild "showery weather; but if certain fungi. Mushrooms are said 



not removed thus early in the autumn, 

 they are best left until the following 

 March. They may be either grown 

 in rows two feet apart each way, or 

 trained in a fan form against a wall. 



ROSE OF HEAVEN. Lychnis Call- 

 Rosa. 



ROSE OF JERICHO. Anastatica. 



ROSE OF THE WORLD. Camel- 

 lia japonica Rosa-mundi. 



ROSE SNOWBALL TREE. Vibur- 

 num Opitlus roseum. 



ROSMARINUS officinalis. See 

 Rosernary. 



ROTATION IN CROPS. There are 

 three circumstances to be regarded in 

 regulating the order in which crops 

 should follow each other: — 1. Each 

 crop should be as dissimilar as possible 

 from its predecessor. 2. The exuviaj 

 of the preceding crop should not be 

 offensive to its successor, 3. A fusi- 

 form-rooted crop should succeed a 

 fibrous-rooted crop, or vice versa 



never to rise m two successive seasons 

 on the same spot; and the production 

 of the phenomena called fairy-rings, 

 has been ascribed by Dr. Wollaston, to 

 the power of the peculiar fungus which 

 forms it to exhaust the soil of the nu- 

 triment necessary for the growth of the 

 species. The consequence is that the 

 ring annually extends, for no seeds 

 will grow where their parents grew 

 before them, and the interior part of the 

 circle has been exhausted by preceding 

 crops; but where the fungus has died, 

 nourishment is supplied for grass which 

 usually rises within the circle, coarse 

 and of a dark green colour." 



Again, exhausting crops should never 

 be grown successively; and the follow- 

 ing observations of one of the best of 

 modern gardeners, the late Mr. G. 

 Sinclair, afford much light npon this 

 point : — 



" If we take the weight of nutritive 

 matter which a plant affords from a 



]. Dissimilarity in the following crop | given space of ground, the result will 

 is desirable, because, so far as the sa- 1 be found to agree with the daily expe- 

 line constituents of the soil are con- I rience in the garden and the farm ; and 

 cerned, every tribe of plants in some j the following figures represent the pro- 

 measure takes from it distinct food. 1 portion in which they stand to each 

 Sir H. Davy truly observed upon this ; other with respect to the weight of nu- 

 point, that, " though the general com- | tritive matter they contain, with their 

 position of plants is very analogous, having exhausted the land : — 

 yet the specific differences in the pro- '•' Potatoes .... 63 

 ducts of many of them, and other well Cabbage .... 42 

 ascertained facts, prove that they must Mangold wurzel ... 21 



