NATURE 
457 
THURSDAY, MARCH 18, 1897. 
. NEW WORKS ON BOTANY. 
An Introduction to Structural Botany. Part 
Flowerless Plants. 
&c. Pp. sve 312. 
Black, 1896.) 
Physiologische Pflanzenanatomie. Von Dr. G. Haber- 
landt, Prof. d. Bot. an d. k.k. Universitat Graz. 
Zweite, neubearbeitete u. vermehrte Auflage, mit 
235 Abbildungen. Pp. xvi+ 550. (Leipzig: Verlag 
von W. Engelmann, 1896.) 
Il. 
By D. H. Scott, M.A., F.R.S., 
(London: Adam and Charles 
N these days, when new text-books of various kinds are 
being poured out more or less indiscriminately from 
the press, it is a pleasure to be able from time to time 
to say of some of them that their own intrinsic merits 
furnish a complete justification for their existence, and 
we can with confidence niake this assertion in respect of 
the two books which form the subjects of this notice. 
Botanists who are engaged in teaching will welcome 
the appearance of the second volume of Dr. Scott’s text- 
book, for it is just the sort of work to put into the hands 
of the elementary student. The first volume, we happen 
to know, has been extremely well received, and this new 
one, which deals with the flowerless plants, merits an | 
equal measure of success. 
The Vascular Cryptogams are illustrated by a selec- 
tion of well-chosen types, and these are fairly completely 
described, instead of being treated in that note-book 
fashion which is only too common in many elementary 
books. The Liverworts, amongst the Bryophytes, are 
illustrated by an account of Pe//ia, a type more suitable 
in every way than is M/archantia, which usually does 
duty in this connection. Indeed, except for the fact 
that the latter plant happened to have been somewhat 
carefully studied by Mirbel, and used later by physi- 
ologists, it is difficult to understand how it came to be 
elevated to the position of a Type, which its complex and 
highly specialised structure render it eminently unfit to 
occupy. 
The Algz are liberally represented by nine well- 
selected genera. We could, perhaps, have wished that 
the term asexual, as applied to the ordinary zoospores, 
might have been replaced by some other word, e.g. 2071- 
sexual. Students are often misled by the use of the 
adjective asexual into imagining the bodies referred to 
are all homologous, both mutually, and also with such 
structures as the spores of vascular cryptogams ; whereas 
in many cases they are more correctly to be compared 
with the various forms of vegetative reproductive bodies 
occurring in these plants. A transitional form is 
well exemplified in the gemmz of Ameura. Possibly 
in instances like that of the four zoospores issuing from 
the oospore of Gdogonium, these cells do really repre- 
sent the asexual spores of the higher cryptogams. 
The book contains far more than a mere description 
of a number of types ; the subject-matter is kept well in 
hand, and a comparative and synthetic method of treat- 
ment runs through it all, thus arousing and sustaining 
the interest of the reader by enabling him to grasp the 
proper relationship of one group of facts with the rest. 
NO. 1429, VOL. 55 | 
- 
In short the book is deserving of the highest praise, and 
it will have a useful and, we hope, a successful career 
before it. 
Twelve years have passed away since the first appear- 
ance of Prof. Haberlandt’s “ Physiologische Pflanzen- 
anatomie,” which was written as a protest against the 
one-sided way in which anatomy was commonly studied 
and taught. Influenced chiefly by the brilliant researches 
and expositions of Schwendener, his object was to show 
that the principles laid down by the Berlin professor 
could be extended and applied to all departments of the 
minute structure of plants—that there everywhere exists 
| a close connection between the anatomical structure of 
an organ and the special functions which it may be 
called upon to discharge. And amongst the varied 
lines of development into which modern botany has 
broken out, few have been prosecuted with greater 
vigour, or explored with such fruitful results, as that one 
of the “ biology” of plants, of which the subject-matter 
contained in the book before us represents one branch. 
The advance here indicated is due, ina great measure, 
to the happily increasing custom on the part of botanists 
to travel in countries other than those of Europe. The 
differences between the vegetation of the temperate and 
tropical lands strike one at every turn; the strenuous 
conditions of competition under which the tropical plants 
coexist appeal at once to the senses, and enable one 
vividly to realise the delicacy with which each organism 
must be adjusted to its whole environment. And the 
same is none the less true when the difficulty of existence 
is more directly correlated with physical and climatal 
surroundings than with the aggressive inroads of Esau- 
like neighbours. 
And thus it has been brought about that the study of 
anatomy, from a physiological or biological point of view, 
has come to-day to possess an interest and importance 
far transcending that to which it could lay claim twelve 
or fifteen years ago. 
But just because of the seductive fascination which this 
aspect of the study exerts on most students of botany, it 
may not be out of place to emphasise the fact that there 
is another side to the matter. It is quite possible to 
attach too much weight to the consideration of the more 
directly adaptive nature of plant structure, while paying 
too little heed to the fact of the persistence or inheritance, 
often through a wide range of genera, of ¢yfes of tissue 
arrangements. For anatomy has a phylogenetic as well 
as a physiological side, although, save in the broadest 
features, this is not perhaps so readily discerned in 
plants as it is in animals. For example, the course of 
differentiation of the wood in the stems of vascular 
plants, and the consequent relations of the protoxylem to 
the later formed woody elements, is astonishingly constant 
for even large groups of genera or species, and In many 
cases it affords far surer indications as to natural affinity 
than most of the external characters by themselves would 
provide. And yet it would often be difficult to indicate the 
special advantage which one or other arrangement confers 
on its possessor ; indeed, it is not impossible that it is to 
this very indifference that its value from a taxonomic 
point of view is to be attributed. 
No doubt, ultimately, the histological no less than 
the grosser external peculiarities of al plants have been 
xX 
