Oogonium Liberation and the Embryogeny of Some Fucaceous Algae. 



ously, not only for a given plant, but also for all plants of the 

 same locality. This simultaneous liberation proceeds in fort- 

 nightly crops on a particular day with a fixed interval after the 

 highest spring tide, the interval varing however in different 

 species." 



As this conclusion was based on observations made during a 

 relatively short time, naturally entire confidence could not be put 

 in its validity. My second visit to Misaki was made mainly to 

 determine this point. 



I arrived at Misaki on the 27th of December, 1909, which 

 was just the day before the highest spring tide. To my disappoint- 

 ment I found that most of the Sargassum growing in that locality 

 had not yet attained their maturity and for some time no general 

 oogonium liberation could be observed. 



The first general oogonium liberation of Sargassum énerve 

 occurred in fact on the 12th of January, the next day after the 

 highest spring tide. Three days later, on the 15th of January, 

 the first general oogonium liberation of Sargassum Horneri also took 

 place. 



So far these observations confirmed in the main the record of 

 the preceding year. But the liberation went on thereafter quite 

 irregularly, without showing any fixed relation to the highest 

 spring tide. The actual state of things is shown in the following 

 table. 



The numbers in the table denote the dates of general oogo- 

 nium liberations. The intervals between two successsive libera- 

 tions is quite irregular, for example, the intervals in Sargassum 

 enerve are 5, 6, 9, 10 or 11 days. But the intervals between the 

 two corresponding liberations in Sargassum enerve and Sargissum 

 Horneri are, as is seen from the table, tolerably constant; namely, 



