THE SOUTHERN CYPRESS. 29 
pronged and multiple roots below the knee, it appears very probable 
that the knees are developed not only for the purpose of increas- 
mg the supply of oxygen which the roots are able to obtain di- 
rectly from the water, but of enlarging and strengthening the basal 
support. The evidence of this belief is (1) the general absence of 
knees in swamp soils superficially dry during most of the year, (2) the 
presence of knees where there is an excess of surface water for long 
periods, (3) the rise of the knees approximately to the height of the 
average flood level, and (4) the interwoven network of.roots in the 
superficial root system, and the anchorage afforded by the mass of 
deep roots beneath the knees. 
REPRODUCTION. 
SEED AND GERMINATION. 
Cypress has the power of reproducing itself both by seed and by 
sprouts from the stump. 
Cypress cones (‘‘balls”) contain from 18 to 30 twisted, sharply 
keeled, or winged seeds! (Pl. XI). Large pockets or sacs in the 
cone are filled with an exceedingly sticky, red, liquid resin, unpleas- 
ant to the taste. This probably explams why the seeds are only in 
slight degree taken as food by either birds or rodents. The outer 
‘coating is thick and hard. When free from cone scales or other 
materials there are about 5,000 seeds per pound. Upon ripening in 
October and November, the seeds fall to the ground near the tree. 
Unlike the seeds of most conifers, cypress seeds are not scattered to 
any extent by wind and animals. Seed is borne in abundance. 
Some is produced almost, every year, and full seed crops, so far as is 
known, occur at intervals of about every three years. Some of the 
seed is aborted or infertile, so that germination averages usually 
from 40 to 60 per cent. 
Tests? of seed collected in the two Carolinas in the fall of 1913 
gave from 55 to 65 per cent of germination (Table 5 and Pl. XI). 
The general average for seed from all sources 1s perhaps 40 to 50 per 
cent. Seeds stored indoors in a warm, dry room from November 
until the following April, 1913, gave 55 per cent germination, occur- 
ring mostly in five weeks and reaching completion in seven weeks. 
Some of the same lot after soaking in stagnant water in a warm room 
for six weeks gave 65 per cent germination, complete in two weeks 
from date of sowing. In another test seed which was kept contin- 
uously moist and aerated under a glass jar for a period of four months 
completed germination m seven days,? with a total of 87 per cent 
germination. 7 
1Size of seed averages from 4 to 3 inch long by 1 to 4 inch wide. 
*Conducted by the writer in greenhouse flats at the Arlington Experiment Station, U. S. Department 
of Agriculture. The seed was collected at random from trees in North Carolina and South Carolina 50 to 
100 years old, and conditions for the tests were practically ideal. 
3In June, 1913. 
