1921] JEFFREY & TORREY—HERBACEOUS ANGIOSPERMS 7 
of storage parenchyma, the foliar ray subtending the leaf trace in 
its vertical course in the stem. Along the inner margin of the ray 
may be seen the elements constituting the foliar trace. Fig. 8 
represents the foliar ray of Helianthus orgyalis, a perennial and 
somewhat more woody species than H. annuus. This is in accord- 
ance with a general principle, for, other things being equal, the more 
woody an herb is, the longer radial and the less tangential and verti- 
cal extension have its foliar rays. Conversely, the more her- 
baceous the texture, the shorter the radial extension of the leaf rays 
and the greater their vertical length. Another feature of contrast 
can be distinguished between the rays shown in figs. 7 and 8. In 
the former the ray is quite homogeneous in structure, while in the 
latter narrower fibrous elements constitute radial bands in the sub- 
stance of the ray. This contrast is a common one between the 
foliar rays of woody and more advanced herbs. 
We may now turn to the relative size of the foliar traces and 
rays in more and less herbaceous forms, as well as the contrasts 
in the structure of the rays presented in these various modifications 
of the herbaceous type. The best way to make these important 
features clear is to choose corresponding regions of the stem, pro- 
gressively more herbaceous in their texture, from different species 
of the same genus. Fig. 1o shows the vertical tangential view of 
a foliar ray from the lowest region of the aerial stem of the somewhat 
woody Helianthus hirsutus. It will be observed that the structure 
of the foliar ray in this instance is far from homogeneous, since 
bands of fibers are common in its substance, and with them vessels 
likewise occur. In this instance the foliar ray is obviously 
in the process of organization from the ordinary wood, namely, 
from smaller rays, separated by strands of vessels and fibers. In 
more advanced herbs belonging to Helianthus, as will shortly appear, 
the fibers and vessels progressively disappear, until the final result 
is a large mass of radial and longitudinal storage tissue, the typical 
foliar ray. 
Fig. ro represents the foliar ray in a condition of aggregation 
from smaller rays. Srnnotr and Barey (6) have denied the 
possibility of the appearance of foliar rays as the result of aggrega- 
tion. Their error in this respect has been pointed out recently by 
Hoar (3), and consequently need not be referred to further here. 
