Til den: PILINIA AND STIGEOCLONIUM. 627 



filament, except that it does not stand upright, with cells in 

 healthy growing condition. On the interior its neighbor consists 

 of a similar cell through more mature which through the 

 swelling of its contents has attained a globose form. The pro- 

 cess of division is far enough along to allow four portions to 

 be clearly discerned and four eyespots are perfectly apparent. 

 They are seen to lie as far from the center as possible. On 

 one side lies a very angular cell, nearly twice as long as 

 wide, containing six zoospores. They are 3.5-4 mic. in diam 

 eter; their eyespots are distinct. A faint though quite dis- 

 tinct movement of the zoospores within the cell was percepti- 

 ble, but though this and other material was watched during 

 the remainder of the afternoon, no spores were seen to escape 

 from a cell. This probably was due to two reasons: first the 

 afternoon is not the natural time for the escape of motile 

 spores, the best time for observing them being from 8-12, 

 A. M. ; second, the material had lain already for same time under 

 the coverglass, so that the poor supply of air and lack of fresh 

 water very likely weakened the natural liveliness of the spores 

 On the opposite side from this was an empty cell from which 

 the spores had escaped probably during the morning hours. 

 These empty cells were very abundant throughout all the 

 plates examined. In the same drawing can be seen such a cell 

 occurring as the basal cell of a filament proving that a basal 

 cell may also be a reproductive cell. However this may be, 

 the combination of, or the relation between, basal cell and 

 filament, in this case is not the same as in the Pilinia basal 

 cell and filament. For this filament is either a Pilinia filament 

 not yet transformed into Palmella cells, or it is the product 

 of a Palmella cell, while the basal cell is certainly a Palmella 

 cell. On the other hand a Pilinia filament as well as the 

 Pilinia basal cell may be the product of germination of a spore. 



It was expected on the following morning to make a more 

 thorough study of the spores and secure other drawings. But 

 when this examination was made the material seemed to be 

 disorganised in great part, though the conditions to all appear- 

 ance remained unchanged. 



Although for the reason stated above, the subsequent be- 

 havior of the microzoospores has not been so closely studied as 

 that of the megazoospores, yet by means of staining, the fact 

 has been clearly brought out that a number of small spores 

 closely resembling those in the plate and solitary cells, are 

 present in nearly every mount of the material containing these 



