B. H. Guilboau for his enthusiastic co-operation at all stages 

 -of the work. I am also indebted to Col. James Breaux, president 

 •of the Oyster Commission of Louisiana, for placing at my dis- 

 posal the data concerning the leased areas in the territory under 

 investigation. 



Methods. 



During the pursuit of these investigations, methods already 

 used by previous investigators have been used wherever pos- 

 t-jible, in order that the results might be more readily compared 

 with those already recorded for other locatlties. 



The salinity of the water was determined in the usual man- 

 ner, Hildegard's Oceanic Salinometer being used. For absolute 

 accuracy in this determination a correction to a temperature of 

 15 degrees centegrade (60 degrees Falir.) must be made; but 

 as the temperature correction in any instance would be so slight 

 as to be of no practical importance, it was neglected in all cases. 

 Tlie sample of water for the salinity determination was taken 

 one foot from the bottom by means of a bottle lashed to a pole. 

 Water from the several stations was examined at various stages 

 of tide, and under various weather conditions. Averages of all 

 these readings were made, and are given in the food tables. 



The apparatus for determining the direction and velocity of 

 the current was modeled after that used by Dr. Caswell Grave 

 in his study of the North Carolina oyster fields, and fully de- 

 scribed in his report, (a) 



For determining the food value of the water over any bot- 

 tom, a sample was collected one foot from the bottom by means 

 of a litre bottle lashed one foot from the end of a pole. When 

 the pole was thrust to the bottom the cork was drawn by means 

 of a string attached to it, and when the bottle had filled it was 

 brought up, recorked and labeled. A number of oysters were 

 tonged from the same locality and three of average size col- 

 lected. The contents of the stomaeiis of these were removed, 

 as soon as possible aftei- they wei-e taken from the water, and 

 the number of diatoms estimated by means of the Rafter Cell. 

 The total numbei- food forms found when divided by three gives 



(a) Caswell C,\ 

 try Of Xurlh CMroli. 



