86 
Review . 
haustoria] are to be regarded as reduced roots can hardly be doubtful 
from all the researches before us/ This can only mean that the 
haustoria are roots morphologically speaking. Instead of such a 
statement we should have expected something like the following, 
which we take from Professor Sachs’s description of Phycomyces , 
mutatis mutandis. 1 Our whole \Cuscuta\ plant is devoid of chloro- 
phyll, and is therefore unable to produce organic vegetable substance 
by decomposition of carbon dioxide ; on the contrary it absorbs it for 
its development out of the substratum, that is, by means of the 
[haustorium] contained in the substratum which, in spite of its 
different organisation, behaves itself, physiologically, exactly as the 
root of the Botrydium and of the Almond, since it penetrates into the 
substratum urged by the same kind of irritability, and absorbs water 
and nutritive matters from it. We are therefore completely justified in 
regarding this portion of our \Cuscuta ] distinguished by botanists as the 
\haustorium\ as its root V 
If Professor Sachs had prefaced his lectures on Roots by saying, 
that for the sake of convenience, and in order to avoid the multiplica- 
tion of technical terms, he proposed to use the word root for root-like 
organs, — no one could have objected. But, though he does not say so in 
set phrase, he certainly gives the impression of claiming for the organs 
in question the legal designation of root, which we could only grant 
them as a title of courtesy. 
The fourth and fifth lectures deal with shoots , — typical, reduced, and 
metamorphosed. With the sixth lecture we find ourselves on familiar 
ground : — ‘ The cellular structure of plants, protoplasm, nucleus, 
cell-wall/ This part corresponds in fact to the beginning of the 
4 Text-book,’ where the morphology of the cell is the first subject 
treated. The facts and illustrations used are, in some measure, the 
same in the two books, but in the ‘ Lectures ’ we find accentuated a 
point of view which, as we believe, does not occur in the Text-book, 
and which is interesting as illustrating the later development in our 
author’s manner of regarding nature. We allude to the secondary 
position in which the cell is now placed. Professor Sachs writes: — 
‘ Cell-formation is a phenomenon very general it is true, in organic life, 
but still only of secondary significance.’ A multicellular plant is 
regarded as a 4 coeloblast ’ (e. g. Caulerpa ), in which longitudinal and 
The italics are our own 
