28 



emphasized by the distribution of the spat on the shells. Of the 

 4963 in the one case 3084 were on the inner surfaces, and of the 

 6977 in the other case 4445 were on the inner surfaces which be- 

 cause of their smoothness remained clean for a longer time than 

 the rough outer surfaces. 



Besides the cleanness of the cultch another factor contributed 

 to the result — the shells were planted in ridges. The advantage 

 of ridges is four fold ; as the shells are strewn thicker most of 

 them are higher off the bottom than they would have been if they 

 had been planted broadcast and the young spat is less likely to be 

 "mudded up ;" in case large tracts are planted the open areas in- 

 tervening between the ridges give an opportunity for the develop- 

 ment of the food supply which is chiefly made up of plants living 

 on the bottom ; the ridges interrupt the currents and produce 

 more irregularities and disturbances than an evenly strewn bottom 

 would make ; and they ofifer a better resistance to the currents 

 which bring the young free swimming oysters, and thus are en- 

 abled to catch more spat. This last fact is well illustrated by a 

 comparison of the results gotten from the ridge planted parallel 

 with the current and the one planted perpendicular to it. 



■ EXPERIMENT II. 



TO DETERMINE WHETHER A SET CAN BE SECURED IN THE GULF. 



Various rumors concerning the supposed existence of natural 

 oyster reefs in the Gulf together with the certainty that at some 

 historic time, the oysters now in Calcasieu Pass must have come 

 from .elsewhere, led to an experiment to determine whether at 

 present any spat may be caught in the Gulf. In order to answer 

 this question it was necessary to plant cultch at points likely to be 

 outside of the range of the river which as observation had shown 

 was full of free swimming fry. The number of shells available 

 for experimental purposes was very small and only two plantings 

 could be made. 



One of these was made in 12 feet of water about 2 miles west 

 of the west jetty and the other in 12 feet of water about one mile 

 and a half east of the east jetty (see map). In choosing the local- 

 ities particular care was taken that they might be well out of the 

 range of the river currents produced by the southwest and south- 

 east winds. During the summer these two winds prevail more 

 than any others. The east planting Station A., was made east of 



