BY R, VON LENDENFELD, PH.D. 329 



Remedy. 



In the oyster beds along the shores of the Mediterranean, 

 sponges of various kinds, especially species of the genus of 

 Euspongia, sometimes smother the oysters in a similar manner as 

 has been observed in the Clarence. 



In Trieste the oysters are grown on submerged trees, on which 

 the spat readily sets and which are taken from the water and 

 divested of their marine fruit as required. 



It sometimes occurs that sponges grow on these oyster- trees. 

 The effective remedy against these sponges is to take the tree 

 from the water during rain. 



The fresh water kills all the sponges in a few hours during 

 which period the oysters are of course not at all affected by being 

 out of the sea. The tree is, after several hours, placed in the sea 

 water again and the sponges rot and fall off. In our case such a 

 remedy can of course not be employed. 



The only suggestion which seems possible is to lead fresh water 

 through pipes to the infected locality, and in this way gradually 

 kill all the sponges. 



