514 
Fig. 479. Fig. 480. 
Phyllophora membranifolia. Fladen, eastern Phyllophora membranifolia. Limfjorden, at Jegindø. 
Kattegat. May. Photo, “/; n.s. July. Photo, ‘/; n.s. 
at the end of a cylindrical stipe. The fan is not plane but convex, turning the convex 
face upwards, towards the light. 
The growth of the particular segments of the frond may continue in the be- 
ginning of the next season (fig. 478), and the primary fan may thus be divided 
into secondary ones. But all the segments of the frond do not keep the growing 
power; several of them definitively cease growing at the end of the season, and, 
at least in older fronds, this may be the case with all the segments of a fan 
(fig. 479, the lowermost fans). In such cases the renewal of the fronds takes place 
only by proliferations arising from the cylindrical part or from the lower part of 
the flat frond. In the plant shown in fig. 478, gathered at the end of April, the 
difference in colour, and the absence of epiphytes characterized the new-formed 
portions of the frond. The proliferations arise as long cylindrical outgrowths that 
later become flattened and forked above. When given off from the flat frond they 
are usually placed on the border, but they may also frequently arise from the flat 
surface of the frond. These proliferations give rise to normal fan-shaped shoots that, 
however, only reach their full fan-shape in the season following their first appearance. 
Cylindrical proliferations without a blade are frequently met with in summer and 
autumn (fig. 480, 481). The production of proliferations may be repeated in the 
new-formed shoots, and 3 (or 4) generations of shoots are therefore easily recognized 
