6 



bright summer-time; the summer leaves are longer tliau the winter leaves. Each 

 shoot has ahvays 3 to 6, most ofteu 4 or 5, full-growii leaves and behind these 

 some sheaths which have lost their blades. As shown distinctly bj' the present photos 

 (Figs.l and 2), it is charaeteristie that the blades are thrown ofT at their base, whereas 

 the sheaths remain for a long time and ouly gradually decay, leaviug uothing 



but the strings as loose fibres. 

 The largest quantity of leaves 

 is thrown off during the autumn 

 in September — October, when 

 the autumnal gales set in cau- 

 sing a rough sea; and as the 

 summer-leaves are besides the 

 longest, it is evident, that the 

 autumn gives the greatest mass 

 of loose leaves. It is also a 

 well-known phenomenon that in 

 tiie autumn loose leaves of eel- 

 grass as also whole shoots are 

 found floating about in the sea 

 in quantities. This large drift 

 which is further inereased by 

 the seine-fisheries, is partly 

 washed ashore, making large 

 mounds (»Eve« or »Erve><) along 

 the beach, and partly sinks to 

 the bottom, where extensive 

 accumulations of »dead-weed« 

 are formed, especially in deep 

 water in holes, chaunels and 

 calm inlets. The »dead-weed« 

 will be a little more closely 

 discussed later. 



The reason why tlie 

 loose leaves of the eel-grass first 

 float in the water and after- 

 wards sink down is, that the 

 fresh leaves or those just thrown 

 off coutain so much air, tliat it makes them float. It is also on account of this 

 air, that the leaves of the growing eel-grass point upwards in the water; as the 

 leaves are extremely flexible, they would iu the absence of air in the blade lie 

 flat along the bottom of the sea, which Mould he quite purposeless in all respects. 

 If a leaf is held up to the light and investigated more closely, it is seen tliat inside 

 it .some fine strings run lengthways iu the blade; their number varies from 3 to 7, 

 but the number of strings in one leaf is the same in the whole of its length. The 

 purpose of these strings, which are connected with one another by some still finer 

 cross-fibres, is to aet as conductors fcir the nutriment of the leaf. Betwecn the 



Fig. 1. Loaf-bcaring shoot of broad-leaved grass-wrack (Mutl-Zostera). 

 At X the blades of the older leaves have bcen thrown otf so that only 

 the sbeath is left ; S is a side shoot. (Soft bottom, 2 fathoms, Kors- 

 havn at Fynshoved, 25. May 1900.) 



