
352 THE NORTHERN MICROSCOPIST. 

adequately realize, much less describe, the order in which these 
currents flow in all their detail, but, broadly speaking, the floating 
particles are disposed in closely contiguous longitudinal series, 
forming together two large more or less oblique bands, and 
separated from each other by two very narrow bands from which 
the green particles of chlorophyll are absent. These colourless 
lines are merely the neutral zone, by whose sides move the two 
opposing portions of the current, up one side and down the other 
side of the cell. They have been called “lines of interference,” 
though not in the sense in which the term is used in physics. 
The cause of this movement so far baffles the investigations of 
physiologists ; it is a dark continent, which no discoverer has yet 
crossed. It is undoubtedly a vital movement, as Corti, its first 
discoverer, stated, and, to distinguish it from the movements of 
liquids in the vascular tissue of phanerogams, it has been called an 
“intracellular circulation.” Similar vital movements take place in 
the cells of many plants, as in the moniliform staminal hairs of 
Tradescantia. 
V.—REPRODUCTIVE ORGANS. 
Reproduction takes place by means of organs which are analogous 
to those found in other cryptogams, but which are by no means 
homologous with them, neither by their development, nor by their 
ultimate form. 
One of these organs is clearly an antheridium, having its own 
special structure. The other organ, or oospore, is open to so 
many interpretations of its morphology, that each investigator, 
coming to his own conclusion as to the correlation of its parts, 
feels it incumbent to invent some new name which, though it may 
baffle the student, stiggests no false analogies, We shall examine 
each of these two organs in turn. 
The antheridia occur in the form of solitary globules of an 
orange or reddish colour when ripe, but in their early stage they 
are green. Their position on the plant varies: in the moncecious 
species of Chara they are usually found below the oospore; in the 
moncecious species of Nitella the respective positions of these two 
organs are reversed; in Lychnothamnus they occur side by side. 
In the dicecious species these relations of contiguity necessarily 
disappear, but in their morphological signification and position 
remain the same. ‘They are mostly in advance of the oospores in 
the order of their growth. 
VI.—SrTRUCTURE OF THE ANTHERIDIUM. 
The antheridium is a complicated structure. Its walls are made 
up of eight flattened cells or valves, termed shields, having lobed 
or wavy edges ; the prolongations of the margin of one valve fitting 

