50 MUSSEL CULTURE 



gain more information as to the time the free- 

 swimming embryos become finally attached than 

 from any other source. For several years Professor 

 M'Intosh has observed the embryos settling first 

 of all in the beginning of June on the small bushy 

 zoophytes which grow on the shells of mussels on 

 the Eden beds. On the buoys and ropes of the 

 local salmon stake-nets also, minute mussels can 

 generally be found in the middle of June. They 

 are described as follows :^ — 



' They appear like grains of millet seed on the 

 zoophytes, and measure from yt to oy inch in 

 length, this variation corresponding to a difference 

 in the stage of development' 



A few lines further on he adds : ' The fry can 

 detach themselves at will, and if the water in 

 which they are confined be impure, they become 

 restless, and, soon forsaking the zoophyte, swim 

 to the side of the vessel, where they swarm at the 

 water-line.' 



Towards the end of September they measure 

 an eighth of an inch. Professor M'Intosh also 

 states that 'the salmon fishermen notice that 

 ropes must be submerged a month, t.e. till about 



^ M'Intosh, Report on the Mussel and Cockle Beds in the 

 Estuaries of the Tees, the Esk, and the Humber, 1891, p. 30. 



