MICROSCOPE IN THE GARDEN. 27 



sharp penknife or razor. The slice, or the sliced 

 part left on the leaf, should now be put on a slide, 

 a drop or two of water added, and covered with a 

 thin piece of glass, when, after a little time, espe- 

 cially in a warm room, the movement will be ob- 

 served (Fig. 83, PI. 3). This movement may also be 

 seen in the leaves of the new water-weed (Anacharis 

 alsinastrum), the frog-bit, the rootlets of wheat, 

 and in the family of charas. In examining the 

 last, the external bark, or rind, should be removed 

 from the cells, or the movements will not be seen. 

 This movement seems dependent on the internal 

 protoplasmic matter which is contained in all cells, 

 and which in these cases appears to be spread 

 over the interior of the cell. It is, however, capa- 

 ble of contraction, and when the plants are exposed 

 to cold, the protoplasmic matter contracts and pre- 

 vents the movement of the contents in the interior. 

 It is, apparently, the extension of this substance 

 beyond the walls of the cell which constitutes the 

 little hair-like organs called "cilia," which are 

 constantly moving, and by the aid of which the 

 spores of some plants effect rapid movements (Figs. 

 13 and 14, PL 1). The effect of these cilia in 

 producing the movements of plants is well seen in 

 the Volvox globator (Fig. 14), which, on account of 

 its rapid movements, was at one time regarded as 

 an animalcule, but it is now known to be a* plant. 

 Cilia are, however, more frequently met with in 

 the animal kingdom. 



Amongst the parts of plants which can alone be 

 investigated by the Microscope, are the stamens. 

 These organs are situated in the flower, between 

 the petals and the pistil, and usually consist of a 

 filament, or stalk, with a knob or anther at its top. 

 If the anther is examined, it will usually be found 

 to consist of two separate valves, or cases, in each of 



