Stomata andHydathodes in Campanula rotundifolia L. 59 
Normal shoot 1 . Both surfaces showed a rise and fall in the number 
of stomata and it was noted that the stomata on the upper surfaces 
were nearly four times more numerous on the top leaf than on the 
bottom one (see Table II, p. 62). 
Shade shoot 2 . The under surfaces in this plant had a fairly uni¬ 
form development of stomata from the base upwards. On the upper 
surfaces, however, the number varied to a greater extent (see 
Table III, p. 63). The number per sq. mm. was less on the whole 
than for the normal shoot (see Table II, p. 62). 
Fig. 1. Diagrams of (a) rotund, ( b ) intermediate, and ( c) linear leaves, showing 
the position of the hydathodes. 
Sun shoot 3 . This plant showed less fluctuation for the under sur¬ 
faces, compared with the normal and shade shoots; with on the 
whole a higher number per sq. mm. On the upper surfaces of this 
plant for the first time, the numbers of stomata in some cases 
equalled or exceeded those obtained for the lower surfaces. The 
average number for both surfaces was much higher throughout the 
shoot than had been noted in the other plants examined (see 
Table IV, p. 63). 
Arrangement of stomata. “Whole” shoot. The under surfaces 
of all the leaves had a row along the extreme margin, otherwise 
they were fairly evenly distributed. On the upper surfaces as a 
1 Grown in a garden, under normal conditions. 
2 Grown under a shady hedge, Newcastle, Co. Down. 
3 Grown on a dry, sandy heath, Edzell, Forfarshire, 
