April, 1919,] THE GERMINATION AND DEVELOPMENT. 81 



a sharp knife and examined tlie samples under the microscope. 

 The weather was more favourable for us this year than in last 

 and we could carry on the work without many hindrances. 



The first sporelings of Porphyra on the block were found 

 this year on 27th of October. The 3'oungest of them were still 

 single-celled. It may be safely stated that in this year the 

 Porpiirra-spores came upon the substratum not long before the 

 said date. 



Repeated to wings with a fine-meshed net were tried on the 

 water about exi)eriment ground and the catchings were care- 

 fully examined. We could not succeed, as already experienced, 

 to find anything in them to be regarded as Porphyr ashore. 



The youngest, single-celled sporelings are roundish elliptical, 

 measuring 10-11 1^. in diameter. The chromoplast is single in 

 each cell, more or less arachnoidal in shape, and holds a nucleus 

 in its center. No other remarkable content is found. The cell- 

 membrane is pretty thick. At the base of the cell there is a 

 short rhizoid which is practically a process of the cell-membrane. 

 (Plate 1, fig. 12 a-b). 



The single-celled sporelings increase in their cell-length and 

 then they are trans veresely septated at the middle of the length. 

 Each of the two cells contains single chromoplast of the arach- 

 noidal form, in the center of which one nucleus is imbedded. 

 Fine granular substance is now richly found in the plasma. 



The lower end of the lower cell is attenuated downwards 

 and penetrates, as it were, into the primary rhizoid, to take a 

 stronger anchorage on the substratum than before. The new 

 rhizoid elongates further as the upper cell divides by more trans- 

 verse septations, and its lower end begins to ramify once or 

 twice. The cell-membrane gets much thickened about the 

 ramified part of the rhizoid as to result in a scutellate disc of 

 hyaline matrix. (Plate 1, fig. 12 d-f.) 



The two-celled sporeling develops further into short fila- 

 ments of 5-7 cells arranged in single row. The apical cell of a 

 filament is rounded at the top and the others are cylindrical and 

 nearly half as short as the diameter. The basal cell still keeps 

 the former state. (Plate 1, fig. 12, f.). Ver}' frequently, however, 

 the first-formed rhizoid may be atrophied, leaving a narrow 



