196 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



to a depth of 8 or 10 feet for a few weeks at a time, and 25 feet 

 for a few days, but does not seem to grow on the immediate 

 banks of the Mississippi and other large rivers whose high-water 

 periods last too long ; except near their mouths where the 

 seasonal fluctuations are necessarily less than they are farther 

 up. Its occurrence on the banks of ox-bow lakes which were 

 once part of the Mississippi River may therefore be used as 

 evidence of the minimum age of such lakes.^ It prefers soil 

 that is rather rich, either from the amount of mineral plant food 

 in the strata penetrated by its roots, or from alluvium deposited 

 by streams. 



The regions where this species grow have a mean temperature 

 of about 53° to 75°, a growing season of 180 to 360 days, and an 

 average annual rainfall of 38 to 65 inches. It is successfully 

 cultivated, however, not only in New York, or even farther north 

 of its natural range, but at the same time in ordinary dry soil of 

 parks and streets. ^ 



The cypress swamps are pretty well protected from fire most 

 of the time by the wetness of the soil or the absence of 

 inflammable material on the ground, but occasionally in a very 

 dry season fire gets into the edge of such a swamp from the 

 neighbouring uplands and kills some of the trees, whose thin 

 bark renders them rather sensitive. 



The wood of our cypress, like that of the Old World tree 

 of quite different appearance which bore the same English name 

 long before ours was discovered by civilised man, is very durable 

 and easily worked, and therefore cut in large quantities for 

 shingles and other articles which are to be exposed to the 

 weather or placed in contact with the soil. The last census 

 reports 955,635,000 feet of cypress as having been sawed in 

 1909, nearly two-thirds of this amount coming from Louisiana. 

 Next in order were Florida, Arkansas, Mississippi, South 

 Carolina, North Carolina, Missouri and Georgia. (Some of this 

 amount, however, possibly 10 per cent., should be credited to 

 the other species of cypress discussed a little farther on.) The 

 soil in which cypress is found is usually too wet for cultivation 

 and not easily drained, so that in spite of the tree's slow growth 



^ See Science, II., vol. xxxvi. pp. 760, 761, November 29, 1912. 



■■2 In such situations its characteristic "knees," the tops of which in a state 

 of nature seem to indicate the greatest height of water to which the tree is 

 accustomed, are developed on a very small scale, if at all. 



