he Go HS agi eee (ira 
By 204. ae tructural bad P Phoysiolog ‘eal Botany. 
the pean. In the autumn, when ihe annual ane dies be hy 
down, the oospore falls to the bottom of the water, the fe 
young plant developing from it in the spring. The first — a 
algoid cells of the young plant are considered a pro- em- Tee 
- bryo, on which the plant itself grows as a lateral branch ~~ 
(Fig. 418 11.). The process of impregnation itself takes — 
place in this manner. At the moment of maturity the neck — 
of the five peripheral tubes of the nucule becomes loosened, Lee 
and between the five clefts thus formed antherozoids pene- 
trate into the oosphere. The Characez have no economi- 
cal or medicinal value, but are of importance in respect to 
our knowledge of the life of plants. 
[Several species of Chara are common in freshwater 
ditches, ponds, and streams, forming tangled masses, easily _ 
distinguished from Algz by the verticillate arrangement of 
the branches, and by the gritty nature of the whole plant —_ 
caused by the deposition of calcareous matter ; when de- ~ 
caying the plant emits an offensive smell, resembling that of __ 
sulphuretted hydrogen. JVite//a is not so abundant, and is 
destitute of the calcareous incrustation. The plant is, in each » 
case, fixed in the soil by slender root-filaments or vAzzozds. 
; The central or axial cell of each internode in Chara is . 
very large compared with the size of the cells which sur- 
round it, and which form the cortical fayer. Each node 
consists of a transverse plate of small cells resembling those 
of the cortical layer, and separating the internodal cells 
from one another. The branches and secondary branches — 
(sometimes called leaves) resemble the stem in structure, the 
latter always ending in a much-elongated pointed cell. The 
apex of the stem forms a compact terminal bud, beneath 
which the internodes become gradually longer as you 
approach the base of the stem. Growth, ze. the formation ~ 
of new nodes and internodes, takes place immediately 
_ beneath this terminal bud, new rhizoids being first formed, i 
and then branches bearing in their axils the reproductive 
organs, which are easily made out as minute orangered 
