7 
Segmentation of the Stem. 
advantages of the “ Sprossglied” doctrine and is a most ingenious 
exposition and explanation of several very important facts connected 
with the articulation of the stem. 
In the final chapter we are made acquainted with the part 
played by the “Sprossglied” in the theory of the plant-individual 
and in phyllotaxis. In this it is shewn that the “Sprossglied” is the 
simplest morphological “individual,” since the “shoot,” the entire 
plant itself, and the cell, all lack certain qualities which are 
necessary in order to qualify for that distinction. Hence Al. Braun 
was in error in regarding the “shoot” as the true “individual.” 
As regards Phyllotaxy the “Sprossglied” theory shews that the 
arrangement of leaves on the stem has not been brought about by 
shifting and displacement of the leaves so as to suit space- 
adjustment on an elongating cylindrical structure, the stem, which 
latter was wrongly regarded as a simple unity in itself bearing the 
leaves as mere lateral “appendages,” as by Hofmeister, Sachs, 
and Schwendener, but as Schumann and Jost have lately shewm 
the positions of the leaves on the stem, as must necessarily result 
from the fact of the latter being built up of “ Sprossglieder” (leaves, 
each with its corresponding “ Stengelglied”),are fixed and invariable 
from the first. 
Finally, the author wishes to impress his readers with the fact 
that the “Sprossglied” doctrine is a necessary consequence of well- 
ascertained facts, of which the development of the monocotyledonous 
embryo takes the first rank. The mericyclic stems of Phanerogames 
with their layered apex stand in a more hypothetical light, but 
“a hypothesis which, by means of logical reasoning, can be 
leduced from well-ascertained facts, will everywhere be regarded, as 
in physics, as the more impregnable and credible the more facts 
which are obscure eventually become placed by it in a clear light, 
and by doing this it affords compensation to the understanding for 
what is lacking in direct evidence appealing to the senses.” 
The reviewer feels that he cannot too strongly insist upon the 
value attaching to this latest contribution by our author, the more 
so as the productions of the latter, unrivalled as he probably is in 
knowledge of, and power of rightly interpreting facts relating to the 
morphology of the higher plants, appear, for some strange reason, 
to be seriously under-estimated or neglected. 
A plate of most lucid and instructive diagrams accompanies the 
letterpress of the paper. W. C. W. 
