MAXUEING IX THEOEY AXD PRACTICE. 



Ill 



striking.asithiisnoble foliage of a rich glaucous blue- 

 green. AraHa Sieboldii (correct name Fatsiajaponica), 

 too, must not be forgotten, as it is quite haiiiy in 

 sheltered places, and has splendid foliage which is ver v 

 distinct in appearance. A. papyri/era (correct name 

 t'atsia papi/riftTv) is even more noble, but, as it is 

 not hardy, plants should be taken up in the autumn 

 ;ind -wTntei-ed in a cold house or shed. The Xew 

 Zealand Flax {Fliormiiim tenor) is also a fine plant for 

 the hard}- fernery, and there are many others that 

 may he used with good effect; -while as to tVms 

 beyond those mentioned, their name is legion, and, 

 as they cost but little to collect or purchase, any one 

 may soon start -with a g<x)d stock of some of the 

 principal sorts. The hest time to do this is early in 

 the spring, just before the young fronds start, -when 

 they not only bear up-rooting without sufEerin"- 

 much injuiy, but they may be split apart and 

 di-iided, and so increased, the only limit to this 

 being the nvunber of separate crowns, each one of 

 which, if carefully removed, will soon form fi-esh 

 roots and grow. Some kinds being more tender 

 than others, it is necessary to afford protection 

 against spring frosts, and keen cutting ^-inds, 

 especially if the fernery is not naturally well shel- 

 tered, as -when the fronds are just forming and 

 unfolding they are easily injured, and if damaged 

 then, are disfigured for the rest of the season. The 

 easiest -way of protecting ferns, and perhaps the 

 most effectual, is to stick in a few Laurel or other 

 evergreen hranches around the north-east sides of 

 each plant, and leave them there till aU danger is 

 over, when they should be cleared away and the 

 surface of the ground cleaned by being freed from 

 weeds, and then mulched by placing a good layer of 

 leaf-soU over the roots of the ferns. This will act 

 very beneficially, as, besides affording much exti-a 

 food for the plants, it -will also assist most materially 

 in keeping the esirth moist, as, being of a non- 

 conducting nature, it prevents evaporation, and 

 therefore when water is given it tells. 



What ferns much like is damping OA-er-head, 

 which is the hest way to apply the water, and if it 

 can he done frequently during the summer, at any 

 time in the evening, the plants will keep in luxuriant 

 health. "UTiat injures them ^d makes them shabby 

 sooner than anything else is the red spider, a tiny 

 insidious insect that makes its appearance in drj- 

 weather; hut if water is resorted to, and adminis- 

 tered in the manner mentioned, the damping will 

 prevent the red spider doing much harm, as it keeps 

 the insect on the move, breaks up its web, and thus 

 stops its increase. 



ManT growers of ferns clear off the fronds in the 

 -winter; but that should not he done, as, hy dis- 

 robing the plants then, they ape left naked at a time 



when they most need their natural covering. 

 Instead of remoA-iug the old dress, it is far better 

 and wiser to add to it by placing over the cro^-ns a 

 few fresh-fallen leaves, cocoa-nut fibre, or common 

 Bracken, which should remain till the young growth 

 pushes its way thi-ough in the spring, when the 

 general clear-up may begin. 



MANURING IN THEORY AND 

 PRACTICE. 



Bt John J. Willis. 



Sb'W Soils become Pertile. — ilany inves- 

 tigations have been made during recent years 

 as to the mode in which nitrification takes place, 

 because ammonia, as such, cannot exist for any 

 length of time in the soil. It rapidly becomes 

 converted into nitric add, in which form it is most 

 invaluable to the gardener as a plant-food ; and the 

 loss of nitrates by drainage is one of the most 

 serious difficulties with which the tiller of the soil 

 has to contend. 



"VMiut. then, are the sources of the nitrogen of 

 vegetation 'r Are they the same for all desciiptions 

 of plants .- Ai-e they to ho sought entirely in the 

 soil or f ntirely in the atmosphere, or partly in the 

 one and partly in the other ? 



These ai-e some of the questions which Lawes and 

 Gilbert have endeavoured to solve hy a series of 

 investigations extending over a period of forty 

 years, and in which they are still engaged; for, 

 although their reseai-chcs have thrown much hght 

 on these questions, they involve great difficulties, 

 and a -vast field of scientific iuquir}- is still left 

 open ; and, no doubt, much laborious work has yet 

 to be accomplished before these questions can be 

 satisfactorily answered in all their hearings. 



From the experiments already made it appears 

 that the bodies j'ielding nitric acid in the soil are 

 — first, the -(-arious nitrogenous organic substances 

 which arise from the decay of vegetable or aniTnal 

 matter ; and, secondly, ammonium salts, either pro- 

 duced in small quantity during the decay of organic 

 matter and carried to the soil by rain, or, in some 

 cases, applied intentionally as manure. A further 

 source of the nitrates contained in the soil is to he 

 found, according to some writers, in the free nitrogen 

 of the atmosphere; but of any supply from this 

 source, other than the ready-formed nitrates con- 

 tained in rain, there is at present no substantial 

 proof. 



The Atmosphere as a Souree of Plant- 

 food. — The combined nitrogen coming down in 



