1904] SPALDING—THE CREOSOTE BUSH 127 
a strong and well-developed 
root system, but that this was 
very poorly developed in those 
that had received much water. 
It was noticeable, too, that while 
the latter were not altogether 
destitute of root-hairs, they had 
not produced them in anything 
like the abundance character- 
izing those that had been given 
little water, there being long 
stretches on which no root- 
hairs whatever were to be 
seen. Both lots of root-hairs 
showed plasmolysis of epider- 
mal cells near the tip of the 
fresh root, and of the adjacent 
root-hairs, with 3 per cent. 
solution of potassic nitrate, 
but farther back in both cases 
plasmolysis was effected with 
difficulty or not at all. As for 
the parts above ground, both 
lots of seedlings had grown 
well, but those that had been 
given too much water were of 
a decidedly lighter green, 
approaching a sickly color. 
From these and other obser- ’ 
vations it appears that when df > 
given an excessive quantity of Ak ) 
water seedlings of Covillea 
make a remarkably rapid ~ 
growth above ground, but pro- 
duce a less number of root- a, 
hairs than those that have a ( 
meager supply, besides show- “ 
FIG. 3.— Seedlings of Covillea eight weeks old, showing effect of excessive and 
meager water supply. 
