A. W. Hill. 
73 
and inconspicuous and are quite different in appearance from those 
of the nodes. Minute starch particles may also be found in the 
chlorophyll-corpuscles of the older internodal cells of the cortex and 
cortical spines. 
No other bodies, which might function as statoliths, like the 
refractive bodies recently described by Giescnhagen 1 and Schroder 2 
in the root-hairs of certain species of Cham, have been detected in 
the lobes or spines of the cortex of this species. This agrees with 
Schroder’s results, since he also failed to find these bodies in the 
stem-cells. 
Although the conspicuous starch grains are developed in some 
abundance only in the nodal cells in the region of which the 
cortical lobes are developed, and also in the cortical nodes from 
which the spines are developed, it does not appear that this 
peculiar distribution of the starch has any relation to the charac¬ 
teristic phenomena of growth exhibited by the cortical lobes and 
spines. 
It seems probable, therefore, that normal geotropic stimuli 
have little or no influence on the direction of growth of the 
cortical lobes and spines, whether of the ascending or of the 
descending order; but that each internodal cell, and its con¬ 
comitant nodal portions, together with the cortex and spines, forms 
a separate and definite system on a minute scale, complete in itself 
with its own centre of attraction,—marked by the zone where 
the cortical lobes meet together,—towards which its members 
grow in opposite directions with conspicuous regularity. 
1 Giesenlingeu. Iter. d. Deutscli Bot. Ges., 1901. Bd. xix., p.277. 
2 Schroder. Beiliefte z, Bot. Centr., 1904. Bd. xvi., p. 27S. 
King’s College, Cambridge. 
Feb. 27th, 1904. 
