256 THE MICROSCOPE. 



Many of the smaller kinds of seeds will reward the 

 microscopist, seen under a low power ; that of Caryo- 

 phyllum (clove-pink), is regularly covered with curiously- 

 jagged divisions; every one of which has a small bright, 

 black hemispherical knob in its middle, represented in 

 % 160, A. 



The seeds of the carrot are remarkably formed, 

 having some resemblance to a star-fish, with its long 

 radiating processes. The seeds of umbelliferous plants 

 have peculiar receptacles for essential oil, in their coats, 

 termed vitce, various points of interest may be noted 

 as occurring in the testae, envelopes of seeds, such as 

 the fibre-cells of Cobcea, and the stellate cells of the 

 Star-anise. 



All plants are provided with hairs; and a few, like 

 insects, with weapons of a defensive character. Those in 

 the Urtica dioica, commonly called the Stinging-nettle, are 

 elongated hairs, developed from the cuticle, usually of a 

 conical figure, and containing an irritating fluid ; in some 

 of them a circulation is visible : when examined under the 

 microscope, with a power of 100 diameters, they present 

 the appearance seen at fig. 145, No. 2. At No. 3, same 

 figure, are represented a few interesting ciliated spores 

 from Confervce. 



The circulation of the fluid-contents of vegetable cells 

 may be examined at the same time with the Chlorophyll 

 globules, by selecting for the purpose the transparent 

 water-plants Chara, Nitella, Anacharis, and Vallisneria, 

 or the hairs of Groundsel and Tradescantia. The circula- 

 tion of the sap in plants growing in water is termed by 

 botanists Cyclosis. 



Fossil plants. We detect in some of the primordial 

 fossils a noticeable likeness to families familiar to the 

 modern algoelogist. The cord-like plant, Chorda filium, 

 known as ' dead men's ropes,' from its proving fatal at 

 times to the too adventurous swimmer who gets entangled 

 in its thick wreaths, had a Lower Silurian representative, 

 known to the palseontologist as the Palceochorda, or 

 ancient corda, which existed, apparently, in two species, 

 a larger and a smaller. The still better known Chondrus 

 sj the Irish moss, or Carrageen moss, has, likewise, 



