The Fur Animals of Louisiana 367 



Treeless Marsh Lands 



As we approach the coast the younger wet areas are 

 treeless marsh, and there are many sea level lakes and 

 lagoons resulting from arms of the sea being surrounded 

 but not as yet completely filled with alluvium. The trees, 

 largely cypress, start their growth near the ridge of the 

 master stream and slowly migrate out over the marsh to- 

 ward some lake or sluggish bayou in the rear. In very 

 young formations, or where the sea water near the coast 

 has prevented the growth of trees, the marsh (fresh or 

 brackish, as the case may be) borders the ridge without 

 the intervening swamp. It is this type of treeless swamp, 

 locally called marsh, that is the typical habitat of the 

 Louisiana muskrat. 



In addition to the swamps and marshes of the delta of 

 the Mississippi there are a number of smaller rivers 

 traversing the coastal plain from the Pearl river, on the 

 southeastern boundary of the state, to the Sabine, on the 

 southwest, which exhibit, in miniature, are replicas of the 

 swamps and marshes of the Mississippi. 



Western Prairie Lands 



There is still an area of Louisiana wet lands which has 

 not been touched upon as yet. The prairies in the south- 

 west portion of the state, formed by almost modern 

 marine deposit, incline gradually to the sea, becoming 

 more and more marshy as we approach the coast. The 

 mud of the Atchafalaya is at present being carried west- 

 ward and deposited in a shallow sea, and beach forma- 

 tions, still extant but far inland, indicate that this condi- 

 tion has existed for some time in the past. Because of 

 these wave and wind built beaches, which act as dykes 

 against intrusion by the sea water, the fresh water in 

 the marsh, furnished by rainfall, groundwater seepage, 

 and springs, tends to remain fresh and at a more or less 

 constant level, producing near the coast a permanent 

 marsh of wide expanse, varied only here and there by 

 lakes and by shell or sand ridges sometimes far inland. 



