52 "^'ol. XLIIL, Art. 1.— K. Yendo : 



September. How the zoospores behave after they are freed from 

 the sporophylls is not satisfactorily known to me. 



The question whether the zoospores of the Laminariaceous 

 plants rest for a certain period after hberation, or germinate soon 

 and pass a considerable time in the state of a protonema-liko 

 body, is not yet satisfactorily solved. The young sporelings of A. 

 crassi/olia are met with between March and May. Late in March, 

 on the coasts about the Tsugaru Strait, bunches of embryonal 

 fronds of this species may be found on rocks, barnacles, mussels, 

 other larger algae or on the sheaths of Potamilla myriopus in the 

 sublittoral reo;ion. Taking one of these bunches we find some 

 fronds already as large as 30-50 cm. in length while some are 

 microscopic, and even protonema-like gametophytes are still associ- 

 ated with them (Plate XYIII, figs. 1-3). This lack of uniformity 

 in the time of outsprouting may perhaps be due to the fact that 

 the spores are discharged during a considerable range of time, as 

 the sporophylls attain their maturity successively from the lower- 

 most upwards, and eventually the spores from the basal sporophylls 

 develop earlier than those from the upper ones. At least in A. 

 crass/folia, the maturing of the sporophylls takes place twice in 

 the life of the plant. I will treat of this further below. The 

 other species found in colder waters, i.e., in the northern part of 

 the Kurile Islands or in Sakhalin, are very likely similar in this 

 respect. Their fully matured fronds are found during August- 

 September, and the sporelings are mostly met with in April-June. 

 According to K.jellman,i) the blade of A. grancUfolia is shed at 

 Spitzbergen in winter. Eosenvenge^) observed the same in north- 

 eastern Greenland. 



1) Kjellman : Spitzbergens Thallophyter, H, p. 11. 



2) Kosen yenge: On the Mar. Alg. from N.-E. Greenland, p. 114. 



