(EDOGONIUM 421 



contents. Cell-division now takes place in the oospore 

 to form numerous cells, from each of which a swarm- 

 spore may be produced. These, may escape by 

 disorganization of the investments, and, after a period 

 of movement, settle, form a cell-wall, and grow into a 

 new thallus. 



The observation of (1), (2), and (3) may be made in 

 early summer ; that of (4) in autumn or spring. 



GEDOGONIUM 



Various species of plants belonging to this genus 

 are to be found growing in fresh water : they are green, 

 filamentous, unbranched Alga3, and are attached at 

 the base to the external surface of submerged plants, 

 stones, &c. The apex of the filament is in some 

 species extended into a thin, hair-like process : there is 

 often considerable irregularity in the thickness of the 

 filament, by which character, as well as by the pecu- 

 liar transversely striated markings of the cell-walls, 

 these plants may be distinguished. 



I, Mount filaments of (Edogonium in fresh water, 

 having gently scraped them off from the surface to 

 which they were attached, and examine them under a 

 low power : observe 



1. The long unbranched filament, of uneven thick- 

 ness, terminated at the apex either by a rounded cone, 

 or by an attenuated process : note also at ' the base the 

 irregularly lobed disk of attachment. 



2. The septa, dividing the filament into a series of 

 cells, with green-coloured contents. 



3. At the upper ends of many of the cells are to be 



