rhe Use of a Simple Microscope. 7 



other such like additions, there will be little difficulty in detect- 

 ing the presence, by a little practice.* 



Disease, as Affecting the Roots, Stems, or Leaves 

 OF Plants. 



It may be considered a rare circumstance to find any one of 

 these parts affected in any way by disease not arising from local 

 injury, without at the same time the whole plant being out of 

 health. We are apt to consider the pulling off a diseased leaf, 

 or the cutting out a withered stem a sufficient remedial treat- 

 ment, but were the rootlets to be examined microscopically it 

 would soon be seen that something here too was wrong. It is an 

 important question open for investigation whether all diseased 

 formations in plants do not commence with an abnormal action 

 at the tips of the rootlets, due to some change within the 

 soil itself, such as undue dryness, sudden accession of a super- 

 abundance of moisture, the application of stimulating manure, 

 either too strong, or applied when the plant is not in a condition 

 to receive it. The moral of this is that the moment anything 

 may be seen to be going wrong, let the rootlets be at once care- 

 fully examined, and a note made of the condition of the soil at 

 the time, as to openness, compactness, or dryness, as also of 

 the treatment which the land may have received just previous 

 to the discovery. An admirable paper on the growth of the 

 wheat plant, by the Hon. and Rev. Lord Sidney Godolphin 

 Osborne, is published in the ' Transactions of the Micro- 

 scopical Society for 1857,' in which this subject is very fully 

 treated ; it is illustrated with drawings of the various parts of 

 the roots and rootlets in their different states and stages, and 

 is well worthy the careful attention of the agriculturist. The 

 experiments were performed in many ways, the plants growing 

 in various materials, and with different kinds of solid and fluid 

 manures, under the higher powers of the microscope (from the 

 ^ inch to the -i- inch), and the actual process of growth was thus 

 witnessed, and its actions noted. "The general conclusion," 

 observes the author, " at which I have aiTived is, that though 

 what I call the epidermic plasm does absorb moisture from the 

 soil — in fact, requires moisture to preserve its elasticity, com- 

 bining in the formative matter it secretes some of the matters 

 presented to it, in whatever medium it may grow — still the great 



* Mr. Norman, of Hull, •well known both as a naturalist and a merchant, \eho 

 has especially studied diatomacese, ■writes, " A little experience will soon show, 

 that whereas certain forms of diatomacea; are peculiar to the Peruvian, other 

 species are only detected in the Bolivian ; while Ichaboe, Californian, Saldanah 

 Bay, and Patagonian guanos contain forms which indicate their former habitats 

 with unerring certainty." — P. H. F. . 



