. 25 



Thus 6977 young oysters were caught on 100 shells of the 

 ridge perpendicular to the current, and 4963 on 100 shells of the 

 ridge parallel to the current. 



DISCUSSION OF RESULTS. 



The number of spat caught in this experiment is certainly very 

 remarkable as it is usually considered that from 10 to 20 young 

 oysters on a single shell is a set. In the present instance there was 

 an average of 49 young oysters encrusted on each of 100 shells 

 from the ridge parallel with the current, and 69 on each of 100 

 shells on the ridge- perpendicular to the current. The result is all 

 the more remarkable when it is considered that in the year during 

 which it was secured the majority of the oysters in the Pass were 

 killed by a freshet. As a matter of fact more spat were caught 

 than could live, as the high death rate shows. 



It is somewhat difficult to account for the size of the two sets, 

 but there are a number of considerations which together make a 

 plausible explanation. In the first place not all the oysters in the 

 pass were killed by the freshet and those which survived though 

 scattered singly here and there and especially in the deeper portions 

 of the river, must in the aggregate have made up a considerable 

 number. In the second place the nature of the currents in the 

 river is most peculiar and may have had a very important influence 

 on the result. 



The work of currents, already emphasized in connection with 

 the transportation of spawn and food, is very important in the 

 process of spawning itself, as it insures the thorough mixing of 

 the sexual elements discharged freely into the water by the adult 

 oysters. In Calcasieu Pass as in the mouth of every river that 

 opens into a tidal basin, complex currents due to wind, river, and 

 tide, occur and it may appear almost commonplace to lay much 

 emphasis on these three factors. However, in this locality, the 

 wind, when sufficiently strong, controls the direction of flow even 

 when opposed by the tidal and river currents. This circumstance, 

 traceable to the physical geography of the region, gives rise to 

 most anomalous irregularities, and as these seem to me to be im- 

 portant, not only as they affect fertilization and the transportation 

 of spawn and food, but in another connection, as yet not empha- 

 sized by oyster culturists. I shall tabulate the various conditions 

 which were observed. 



