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OBSERVATIONS ON THE PLANKTON OF LOOE POOL. 

 By RUPKRT VALIvENTIN. 



The Loe, or Looe Pool, the largest lake in the west of 

 England, is situated in the north-eastern extremity of Mount's 

 Bay. It is about a mile and a quarter in length, and varies in 

 breadth from 500 to 4000 feet ; the approximate surface being 

 about 163 acres. It is separated from the sea by a bar composed 

 of sand and small stones about 600 yards in diameter. This lake 

 is fed by several small streams which drain the surrounding 

 country ; the largest of these being the Cober, which rises in the 

 hilly district of Wendron. After winding at the foot of the town 

 of ITelston, this stream flows along the Looe valley, and finally 

 empties itself into the upper portion of this pool. Besides 

 draining that portion of the country through which it flows, the 

 Cober also receives the sewage from the town of Helston ; 

 and during the summer, and especially if there has been an 

 absence of rain for some weeks, the odour arising from it is by 

 no means pleasant. In spite of this drawback, trout seem to 

 thrive in it ; and I have seen these fish rise at a natural fly when 

 the water was quite turbid owing to the presence of suspended 

 organic matter. 



During exceptionally heavy gales of wind from the south- 

 west and south, the sea has been known to make a breach in this 

 sand-bar, and a large quantity of salt water has thus been added 

 to the fresh water in the pool. 



These and other peculiarites connected with this body of 

 water seemed to make it an ideal lake wherein to study the 

 changes of the floating fauna. 



Early in the spring of 1900 Mr. J. D. Enys asked for, and 

 obtained, permission from the owner, Captain Rogers, E.A., for 

 me to tow-net in the pool. I must here record my thanks to Mr, 

 Enys for much assistance and advice in connection with these 

 investigations ; and also to the courteous owner for placing at my 

 disposal a boat whenever I required one, as well as for permission 



