In addition to the moocjsins. which wo Ravo up counting, we 

 encountered sever j1 water snakes known locally as Water Pilots: 

 these may ^row to five feet in length They were all in small 

 muddy pools in bright sunlight. They are the fastest swimmers 

 among our snakes. Then there were numbers of the ceramic- 

 looking green tree snakes twined around palmetto stems and 

 looped over, just lying about on. or gliding through the Spanish 

 moss Looking even more like porcelain were thousands of little 

 green tree frogs stuck onto things everywhere: and. to complete 

 the color picture, in the shafts of sunlight the leaves were dotted 

 with the delicate little anoles or fence lizards, all exhibiting 

 their brightest green livery. The whole place was also alive with 

 very tropical-looking butterflies, mostly various swallowtails, 

 and all manner of fascinatingly constructed cocoons and egg 

 masses of insects were attached to the Spanish moss. 



There have been four major phases and one subsequent 

 minor or unsuccessful— phase In its formation These you can 

 identify by plotting the direction of flow of successive lengths of 

 the river, starting from the "narrows" about its junction with 

 the Red River, as shown by the arrows on the map In this 

 chapter The Mississippi originally "wanted" to go straight out 

 to sea. which was somewhat west of south, and this it did for a 

 time: but. although the sea was shallow and had only a very 

 small tide, it also had a considerable current that whirled clock- 

 wise around the almost circular coast of the Gulf of Mexico (and 

 now gives rise to the Gulf Stream to the east). This shifted the 

 mouth of the Mississippi over to the east, grubbing away at its 

 delta on the west side and redepositing the material on its east 

 side. Matters continued fairly static until a period of less rainfall 

 occurred to the north; then the river lost out to the sea and Its 

 mouth got pushed off to the east. Next the river regained the 



HOW TO BUILD A DELTA 



This place is situated at a most strategic spot in the great delta 

 of the Mississippi River, close to the present main exit of that 

 river, and just south of the junction line between the coastal 

 marshes and the older deltaic swamplands. It lies in the middle 

 of the eastern quarter of the delta and is an ideal place for ob- 

 serving most of the remarkable features of this extraordinary 

 province: and it is still unspoiled. 



Deltas are very particular things. Imagine a great river like 

 the Mississippi for tens or hundreds of thousands of years busily 

 gnawing away at the edges of a great basin of land up to the 

 very tips of its every tributary, and hauling all the loose material 

 downstream. Where its flow is swift enough, it will move 

 boulders: where slower, mere silt; and the constant pressure 

 from behind keeps it moving along fast enough to do the latter 

 till it reaches the edge of the continent. Here it may encounter 

 one of several conditions. It could find the bottom of the sea 

 tumbling over a gigantic submarine escarpment with oceanic 

 currents roaring by. In this case its silt would be whipped away 

 If. on the other hand, it hits a shelving, shallow coastal sea. 

 especially one without much tide, its waters will push out and 

 come to a slow stop and its silt will be spread far and wide. If 

 this happens, the sea thereabouts rapidly begins to fill up. This 

 causes the river to bade up and drop its silt more quickly until, 

 one would imagine, it had completely dammed itself and started 

 a great inland lake. But it doesn't proceed that way. 



First, the ponding of the river, or rather its tendency to back 

 up. causes it to push harder and so cut channels through the 

 obstruction ahead. Second, the surface layers of the crust of the 

 earth under this mass get squeezed and compacted and then 

 begin to sag. so that each layer forms a great bowl. This relieves 

 the tension temporarily and permits the river to win the next 

 round by piling ever more of its silt on top. Actually, both 

 processes are going on simultaneously: but there are great 

 swings, in time, controlled by several factors. The sea level may 

 diange, the whole crust of the earth may rise or fall due to 

 crustal movements, and the rainfall in the river's drainage basin 

 may vary so that more or less silt is available and the speed of 

 the river is increased or reduced. That such variations have taken 

 place during the formation of this delta may be seen from a 

 glance at the map. 



Facing page: The bayous are mostly muddy, but among the 

 marshes are limpid waters crowded with fish, snails, and 

 other small fry that form the food of wading birds. 



The Snowy Egret, really a small heron, is again one of the 

 commonest birds around the Gulf-coast lands. It has bright 

 yellow feet and is often called "Golden Slippers." 



