26 P. ORPEN BOWER. 
In the parenchyma, which thus separates all the four vascu- 
lar masses, arise two zones of cambium, one surrounding each 
of the xylem masses. The further development which may 
take place is unknown to me, since fig. 21 represents a sec- 
tion from the root of the oldest seedling as yet examined. 
It will be noticed that the outer layers of the pericambium 
divide, and that the process begins opposite the phloem 
masses, though opposite the xylem they remain for some 
time undivided (fig. 22). This corresponds to the fact pre- 
viously noticed, that the complete cuticularisation of the 
bundle sheath, and throwing off of the cortical tissue, are later 
opposite the xylem than at other points. By this division 
of the pericambium a secondary layer of protecting paren- 
chyma will be afforded to the central cylinder. 
It may here be observed that no development of lateral 
roots has been found in the young seedlings of Welwitschia, 
with the exception of the one abnormal case already men- 
tioned. Immediately above the injured apex a lateral root 
had been formed; but I had not the opportunity of in- 
vestigating the histology of this lateral root, or its mode of 
origin. . 
Conclusion. 
The general result of these observations is to show that, 
in its early stages of development, Welwitschia corresponds 
with those plants to which its alliance has already been 
demonstrated. Especially striking is the similarity between 
the germination of Welwitschia, and that of Ephedra 
campylopoda, a similarity which may possibly be found 
to be even closer than as yet recognised, if opportunity 
be afforded for further experiment on the variations in the 
‘process of germination, induced by the position in which the 
seed is sown. Externally the case of Welwitschia, as seen 
in fig. 5, resembles that in Ephedra campylopoda, when the 
seed is sown flat. It would be interesting to know if there 
be in Ephedra, under any circumstances, a development 
analogous to the feeder of Welwitschia. 
As to the morphological value of the latter organ, it has 
been seen to be formed by the lateral extension of the cortical, 
and epidermal tissues of the hypo-cotyledonary stem; this 
extension being accompanied by divisions of the cells of the 
cortical tissue. Its morphological value is then that of an 
emergence. Its physiological function is plainly that of 
transferring nutritious substances from the endosperm to the 
seedling. In the higher plants the physiological function 
of transference of nutritive stuffs, when carried on by any 
