23 



With regard to the sheltered piaces, it is necessarj' to distinguish between 

 piants growing in shallow and deeper water, a difference whicli does not exist in 

 open waters, and the reason for this distinction lies in the nature of the bottom 

 soil. Close under the land we usually find a belt with firm bottom, mostly dark- 

 coloured sand, and the grass-wrack growing on this soil is much like that of the 

 open water; but at P/-, to 2 fatiioms and outwards the soil consists of soft mud, 

 and here we meet tlie true Mud-Zostera. The grass-wrack of the shallow water is 



Fis. 5. Snmll-leavccl Zostera from sliaUo\v water at Holckcn- 

 bara near Nyborg; at x the sbeddiiig plaoci. 

 (Firm, sandy bottom, I'/, to-, 9. VIII. 01.) 



Fig. G. Broad-lcaved Zostera (Miid-Zostera) from dep|ier 



water at Holekenhavn near Nyborg ; at x the sheddiiig 



piaces. 



(Soft, miiddy groiind, 3'/, fm., 9. VIII. ()l.) 



narrow-leaved and short (fig. 5); the length of the leaves varies from 30 to IGO cm. 

 and the breadth from 2.5 to 4o mm. (see Table I, p. 8). The true Mud-Zostera 

 (fig. G) on the other hånd reaches a length of ca. 100—240 cm. and a breadth of 

 ca. 5 — 8 mm. (see Table II p. 9, where for the sake of comparison we sliould 

 consider the measurements for the late summer, as the observations from other 

 piaces were made at this time of year). 



In the Table of measurements (p. 44) is given a .simiiar series of measure- 



4 



