Half-hours with the microscope : being a popular guide to the use of the microscope as a means of amusement and instruction / illustrated from nature by Tuffen West.

  • Tuffen West
Date:
[1875?]
Catalogue details

Licence: Public Domain Mark

Credit: Half-hours with the microscope : being a popular guide to the use of the microscope as a means of amusement and instruction / illustrated from nature by Tuffen West. Source: Wellcome Collection.

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    become marked, by their peculiar method of growth (Fig. 40, PI. 2). The va.scular tissue ot |)lants is either jilaiii oi marked iu its interior. If we e.xamiiie the ribs ot leaves, the green stems of plants, or a longitudinal section of wood, elongated fibres, lying side by side, are observed (Fig. 48, PI. 2). Tliis is what is calleil “ ligneous” or “ woody” tissue, and the greater part of the wooii and solid parts of plants are composed of this ti.ssue (Fig. 2.“19, PI. 8). 'I'he fibres lie in bundles, and are divided from each other by cellular tissue. This latter, in the woody stems of trees, constitutes the “ medullary mys,” which are seen in transverse sections of stems, extending from the ])ith to the bark. The dillerence obst'rvable in the distribution of the woody fibres ami the medullary rays rondel’s the examination of transvei’se st*etions of the stems of plants a subject of much interest (Figs. ^)1, 52, 55, PI. 3). In the transverse sections of stems of most ]>lants, large oj»en tubes are ob- served (Fig. 51, PI. 3). These are calletl “ duct.s.” Such ducts may be well observeil in the tmnsvt'rse section of the common nulish (Fig. 4G, PI. 2) and other roots. These ducts are often marked by pore.s, or dots, and are hence called “ dotted ducts.” These dots are the result of dejiosits in the interior of the tube of which the duct is formed, and a great variety of such markings are found in the interior of vascular tissue. One of the most common forms of marked vascular tissue is that which is called glandular woody tissue (Fig. 49, PI. 3). This kind of tis.sne is found in all plants belonging to the cone-bearing, or fir tribe of jdants. In order to discover it, recourse need not be had to the ganleu for gi’owing plants, as every piece of furniture made of deal wood will afford a ready means of obtaining a specimen. All that is necessary to f 2