134 The Microscope. 



plant, or on different plants, when the inflorescence is called re- 

 spectively monoecious or dio:>cious. They are often accompanied 

 by variously-shaped filaments, generally hair-like, called para- 

 physes. 



" The mature antherids are generally club-shaped, stalked 

 bodies, (spherical in Sphagnaceffi) the outer layer of their cells 

 forming an enclosing wall, while each of the small and numer- 

 ous crowded cells in the interior develops an antherozoid. These 

 bodies are spirally-coiled threads of protoplasm, thicker at the 

 posterior end, and tapering to a fine point at the anterior end, 

 where they are furnished with two long, fine cilia, whose vibra- 

 tions set them in constant motion. When the antheridium is 

 mature its wall ruptures when wet, and the sperm-cells escape 

 in a mass of mucilage ; the walls of the sperm-cells break, and 

 the antherozoids (or spermatozoids) are set free." 



The archegones, or female sexual organs, are shaped like a 

 flask with an oval body and a very long neck. In the lower or 

 enlarged portion (the venter) there is one cell much larger than 

 the rest, the central cell. This becomes divided by a horizontal 

 septum into the two parts ; in the lower and larger part the 

 germ-cell, or oosphere, is developed. The neck of the archegonium 

 is occupied by a single row of cells, the canal-cells. Before im- 

 pregnation these canal-cells are transformed into mucilage, forc- 

 ing apart the four apical or lid-cells of which the so-called stig- 

 ma of the archegone is composed, and forming an open canal 

 through which the artherozoids may reach the oosphere. 



The structure of these various organs may easily be examined 

 by again resorting to Fimaria hygrometrica. This moss is espe- 

 cially suitable for purposes of demonstration because of its very 

 Common occurrence,[and because at almost any time of the year 

 it may be found in all stages of development. Select a stem 

 bearing a tuft of modified leaves at its apex, which may readily 

 be done with the aid of a hand magnifier, or even with the 

 naked eye, and either make longitudinal sections with a sharp 

 razor, or with a pair of fine pointed forceps pluck ofl" a few of 

 the upper leaves and tease them apart with needles under the 

 dissecting microscope. Sections will of course show better the 

 relative arrangement of the parts, while the teased prepar- 

 ations are best'for examining the individual organs. On ex- 

 amining the^preparations in a; drop of Avater under an inch or 



