Anatomy of the Cohort Umbelliflorae . 61 
from the wood parenchyma, since they have very thin cross partitions which 
lack the middle lamella. In PI. V, Fig. 13 one may see the radial view of 
Acanthopanax senticosus . Upon the right appears a single row of parenchyma 
cells adjacent to a vessel. It may be seen that the end wall of the vessel is 
pierced by a simple elliptical pore. The above characteristics show through¬ 
out the genera studied, though in many cases the presence of septate 
tracheides serves partially to obscure them. 
In the last family, the Umbelliferae, I found the same conditions 
of parenchyma as that characteristic of the Araliaceae. In PI. V, Fig. 14 we 
have a transverse view of Cicuta bulbifera . At first glance no parenchyma 
is seen, but upon further study the end walls of the parenchyma cells with 
their simple pitting may clearly be observed. These cells, it will be 
noticed, lie adjacent to the vessels. Fig. 15 is that of a tangential view of 
the same species. Here also the parenchyma shows itself to be only 
adjacent to the vessels. In Fig. 16, which is a radial view of Cicuta bulbi¬ 
fera , we see an example of the vasicentric parenchyma characteristic of 
the family. It also shows the end pore of the vessel. Here it will be noticed 
that the pore , is rounder, and that the end wall is more at right angles 
to the lateral walls than was the case with the Araliaceae as shown by 
Acanthopanax senticosus. 
In Fig. 17 and in Fig. 18 are seen good examples of diffuse and 
of vasicentric parenchyma, in cases where such a condition has been 
recognized. Fig. 17 is that of a transverse view of Juglans nigra , and 
shows the diffuse type, while the vasicentric type is illustrated by the 
transverse view of Fraxinus americana as shown in Fig. 18. 
To sum up the results of my study, I find that in Cornaceae the 
parenchyma, where clearly present in specimens studied, constantly shows 
a diffuse distribution, and the vessels possess the scalariform type of perfora¬ 
tion in their end walls. Native species show parenchyma of varying 
abundance, but nevertheless quite evident, and the rays small. In exotic 
genera, on the other hand, the parenchyma, where present, is scarce, and the 
rays are larger and much more abundant. The wood in the latter case 
sometimes shows septate tracheides, though they are not at all characteristic 
of the family. In Aucuba japonica spiral thickenings often occur upon the 
tracheide walls. 
In the Araliaceae the parenchyma is always vasicentric. The vessels, 
moreover, show usually simple elliptical pores in their end walls. These 
pores are usually at a strongly oblique angle to the lateral walls. Septate 
tracheides are a common character of the family. 
The Umbelliferae show the parenchyma vasicentric as in the case 
of the Araliaceae. The end wall of the vessels, also, usually show simple 
pores. Here, however, these are nearly round in circumference, and are 
nearer at right angles to the lateral walls. 
