146 The Irish Naturalist. [July, 



is no cortex and the internodal cell shows well under the 

 compound microscope the streaming or rotation or C3 7 clo- 

 sis of protoplasm of which fuller accounts have been quite 

 recently published. The tips of the leaves serve equally well 

 for examination. The protoplasm of the older internodal cell 

 contains many nuclei and they may be seen dividing directly 

 or by " fragmentation", a mode of nuclear division rarely seen 

 in the higher plants. For a detailed and illustrated account 

 of the characters ot the stem, leaf, mode of branching, etc., 

 readers should consult a general text-book of botany. Here 

 it would be quite out of place. The Characeae are found in 

 fresh and in brackish water — in canals, ponds, dug-out quarries, 

 clay-pits, bog-holes, etc. In some cases, as in Chara fcetida, 

 their smell is anything but agreeable. The sexual organs of 

 the Characeae are well-marked and are always derived from the 

 leaves. In some cases the male organs — antheridia — and the 

 female organs — carpogonia or oogonia or "nucules" — are 

 found on the same plant (monoecious), in other cases on 

 different plants (dioecious). They are to be found on different 

 species from spring to autumn, and occasionally make their 

 appearance in very early spring before the ice, which rarely 

 comes in Ireland, has disappeared. They are found in con- 

 nection with the whorls of leaves and are generally recognis- 

 able, by the naked eye, as bright orange or red specks. The 

 male organ — the antheridium or globule — is round and 

 contains a very large number of male cells or antherozoids 

 which, when set free, swim about in the water by the aid of 

 two long lashes or cilia. These antherozoids differ from those 

 of all other algae in being spirally coiled, like a cork-screw — 

 the Characeae agreeing in this respect with the Mosses, and 

 Liverworts, &c. 



The female organ — oogonium or carpogonium — is larger and 

 more cylindrical in form. The egg-cell — ovum or oosphere — 

 is enclosed in its cell-wall and is further protected, before 

 fertilisation, by becoming surrounded by five spirally twisted 

 filamentous cells — the involucre or pericarp. The tips of 

 these cells meet at the free end of the oogonium and become 

 cut off by horizontal walls to form the corona of five cells in 

 tne Charetz or of ten cells in the Nitellea. At the time of 

 fertilisation the corona cells separate ; through the canal so 



