1887. | BOTANICAL GAZETTE, "7 
everywhere absent, the only means provided the foot-passen- 
ger for getting across such places being what is called the 
‘‘foot-log.”” The foot-log causeway is a characteristic insti- 
tution of subaqueous Carolina. It consists of logs, usually of 
bald cypress, strung across the stream, and supported at the 
ends by piles driven a few feet into the soft ooze beneath. 
The upper surface is chipped off, so as to furnish a level and 
slippery pathway of some twelve to sixteen inches breadth. 
Frequently, after getting half way across some wide lagoon 
or stygian stream, the wayfarer is confronted by a yawning 
chasm, where the connecting logs have been swept away by 
the rising flood. It may be, too, that the twilight is fast 
deepening into the Egyptian darkness of the cypress swamp. 
Then the belated traveler must wade if he can, swim if he 
must. 
The most abundant trees of all this wet region are the 
valuable black gum and bald cypress. The latter often rises 
to a height of over one hundred feet, and attains a girth of 
twenty-five feet or more above the swollen base. here the 
trunks are not overcrowded, each one is surrounded by a 
palisade of cypress knees. The use of these curious excres- 
cences can perhaps be explained by some of our biologists. 
Some one has suggested that they are intended to protect the 
sapling tree from injury by floating ice, a service, indeed, 
they are well fitted to perform, only it must be remembered 
that ice and the current to give it momentum are both usually 
absent from cypress pools. It may be, however, that the 
Swamp water, which has a strongly acid reaction, acting 
upon the soft, spongy texture of the wood, has something to 
do with the production of ‘these apparently useless appurte- 
nances, as well as the swollen base of the trunk itself." 
he cane, Arundinaria macrosperma, mingled with Scir- 
pus lacustris, Typha latifolia, and Smilax laurifolia, forms an 
impenetrable jungle along each side of the road, which it 
would soon invade were it not for the corduroying process. 
Separating the basins of the different swamps are ridges 
of higher ground, usually with clayey soil. These oe 
i “A Grayii, Du- 
Tivularis, C. flavescens, C. flavicomus, an . Grayii, 
lichium spathaceum, Fuirena squarrosa, Eleocharis tubercu- 
ACRE SRT 
‘The ordinary function assigned to “ eypress kness”’ is that they permit the access of 
air to the roots. “Also see BOTANICAL GAZETTE, Vili. 236.—Eps. 
