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M. Fo^lie. Remarks on forms of Ectocarpus and Py aiella. 



127 



There is al so some difference in raraification, and the chro- 

 matophores are band-shaped, more or less branched. In 

 Ectocarpus has sometiraes been fonnd fructificative organs 



like those in Pylaiella and, on the contrary, in the latter 

 genus like those in Ectocarpus. Therefore, most of the an- 

 thors give to Pylaiella only the range of a subgenus. I am 

 most inclined in accordance with K j e 1 1 m a n 1. c. still to 

 keep it a separate genns. However, I have al so now and 

 then met with the named abnormal forms of fructificative 

 organs. Thus I found last summer Ectocarpus siliculosus f. 

 hiemalis provided with 2 intercalar gametangia below the 

 tip of a branch, respectively 140 and 80 \k long, cylindric, 

 35 \k thick, separated from each other by 2 vegetative cells 

 and, in the same specimen, i 7 intercalar sporangia in chain 

 like those 'in Pylaiella. In this specimen was not found other 

 sporangia, but, on the other side, typical gametangia were 

 very numerous. In E. fasciculatus I also found intercalar 

 gametangia sitnated in the main axis, 5 in a row in a length 

 of about 500 (x, separated by 1 — 3 vegetative cells, and 

 one of the gametangia provided with a deep lacing in in 

 the mi d die. ln another specimen the cells in a couple of 

 branches with side-placed gametangia were, in the middle 

 of the branch, transformed into gametangia in a length of 

 50—300 \k except the cell from which a side-placed game- 

 tangium rised. On the contrary, I have seen specimens of 

 Pylaiella Moralis bearing, besides a number of typical inter- 

 calar gametangia, termin ate, subcylindric ones provided with 

 a hyaline hair like those in E. siliculosus f. hiemalis. 



It seems to be impossible to draw any limit between 

 Ectocarpus siliculosus and E. hiemalis. Typical specimens 

 are easely recognized, but transitions are rather numerous. 

 I have not seldom seen specimens that rnay be referred to 

 either of them. I therefore consider the latter as a form 

 of the former. I often also have seen specimens of E. sili- 



