changes taking place in the topography. In the section be- 

 tween Cat Island Lake and Timbalier Bay there are islands in 

 all stages of disintegration : some of them are barely above the 

 surface of the water, while the former location of others is 

 marked by the tops of the dead grass and bushes which alone 

 extend above the water. Farther inland there has been a very 

 noticeable increase in the area of many of the lakes, and some 

 of them are several times as large as they were fifteen or twenty 

 years ago. The making of artificial cuts has, in some instances, 

 changed the drainage so that former deep places have become 

 filled up and the oyster reefs covered, while other localities be- 

 come better fitted for the growth of oysters, and whenever any 

 clutch is available a new reef is. started. 



The inland bodies of water may be sei)arated into three 

 divisions in respect to the salinity of the water. In all of the 

 bays, lakes and bayous to the west of Grand Pass des Isles 

 the salinity of the water is directly affected by the flow of fresh 

 water from the Atchafalaya River through Four League Bay 

 and Blue Hammock Bayou. These bodies of water receive also 

 the discharge from Bayou Grand Caillou and from Little Bayou 

 du Large. In times when the Atchafalaya River is high there 

 is a noticeable lowering of the salinity in all of these bodies of 

 water, while at any time the water is less saline than in those 

 farther to the eastward. In the second division, between Grand 

 Fass des Isles and Cat Island Lake, there is very little drainage 

 from the upland and the water in the bays and bayous is of 

 })ractically the same salinity as that in Lake Pelto. In the sec- 

 tion to the east of Lake Pelto the fresh water from Bayou 

 Little Caillou anri Bayou Terrebonne is discharged, and here 

 the water is less saline than in the section above Lake Pelto; 

 although, except in times of very severe freshets, the salinity 

 is not so low as in the bodies of water to the west of Grand 

 Pass des Isles. 



Over all of the territory included in this study the ticfal 

 currents are very strong, and are not so much influenced by 

 the wind as they are farther to the westward along the coast. 

 In some of the larger bayous the currents run from two to four 

 miles an hour under normal weather conditions; while in se- 

 vere storms from the South the velocity of the current may 



