Half-hours with the microscope : a popular guide to the use of the microscope as a means of amusement and instruction / by Edwin Lankester.

  • Edwin Lankester
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Half-hours with the microscope : a popular guide to the use of the microscope as a means of amusement and instruction / by Edwin Lankester. Source: Wellcome Collection.

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    at figure 126. Id the passion-flower, three rings are observed upon them, as though they had been formed with a turner’s lathe—figured at 127. In the common mallow, they are covered all over with little sharp-pointed projections, like a hand-grenade. These are represented at figure 128. The micro- scopic observer should make himself acquainted with the forms of pollen grains, as, on account of their small size and lightness, they are blown about in all directions, and may be found on very dif- ferent objects from those in which they have been produced. Some absurd mistakes have been com- mitted by confounding pollen grains with other forms of otganic matter. Thus, pollen grains in bread were regarded as bodies connected with the production of cholera. The pistil, which is the central organ seated in the midst of the stamens in the flower of plants, will afford a great variety of interesting points for examination with the Microscope. In the earliest stages of the growth of the pistil, thin sections of it may be made, and the position of the ovules observed. In the ovule will be found the embryo sac, a central cell, which, on being brought in contact with the pollen grain, gi'ows into the seed. The seed contains the embryo, or young plant. In most plants this is sufficiently large to be seen by the naked eye ; but it may, nevertheless, be examined with advantage by a low microscopic power The seed is covered on the outside with a membrane, which is called the “ testa.” This membrane is often curiously marked, and the whole seed may be examined as an opaque object with the low powers of the Microscope. In order to do this, the light must be shut off from the mirror, and, the object being placed on the stage, a pencil of light should be thrown upon it by the aid of the