NOTES ON T|IE BALD CYPRESS. lo 



of the malarious conditions that now render extensive regions in the Mis- 

 sissippi Valley unfit for the occupation of man. None of the sj)e('ies of 

 the Eucalyptus can be exi:>ected to flourish in the region north of Louisiana. 

 I am disposed to doubt the great febrifugic power of this much talked of 

 tree, and to question whether it does more than hinder the ground from 

 becoming a good nidus for spores by keeping it permanently covered by a 

 mass of leaves that are filled with gummy matters. Such deposits are 

 probably prejudicial to the peculiar plants that pi'oduce the malarial spores, 

 while, at the same time, they favor the retention of permanent moisture 

 that also tends to prevent the production of malaria. 



I have before this called attention to the fact that it is not the wetness of 

 the swamp areas that favors the production of malaria, but the alternation 

 of wetness and dryness with the changing seasons. Whatever operates to 

 arrest, to any considerable degree, these changes of water level in the 

 swamps will contribute, in the same proportion, to the diminution of the 

 malaria generated there. 



At present the course of events is leading to a considerable reduction in 

 the number of cypress trees in our Western swamps. Although the busi- 

 ness is manifestly in its beginning, there are some hundreds of thousands 

 of cypress trees cut out of the swamps of the Mississippi Valley each year. 

 As there is no replanting, the result is to give an advantage to the worth- 

 less and malaria-breeding cottonwoods, pin oaks, and other swamp trees, 

 or to leave the swamp open to the festering heat of the sun in case these 

 species cannot crowd into the places made A'acant by the removal of the 

 cypresses. The extension of this process will convert into unshaded pools 

 a great many swamps that are now made comparatively wholesome by the 

 deep shade that this tree secures to them. 



