70 NATURAL SCIENCE. Jan., 
As far back as plants are known, even in the problematical 
Nematophycus of the Silurian, rings of growth are visible in certain 
orders, but whether these are true ‘‘annual rings’? we have no means 
of telling. When we study the evidence derived from fossil floras 
found within the Arctic regions, we are on safer ground, for the 
Devonian, Carboniferous, Jurassic, Cretaceous, and Lower Tertiary 
plants could not possibly have lived there under present climatic con- 
ditions. Still clearer is the evidence when we come to more recent 
times, and find alternating deposits containing northern and southern 
plants of existing species. 
Les Licuens. By A. Acloque. ([Bibliothéque Scientifique Contemporaine.] 
Pp. vili., 376. Illustrated. Paris: J. B. Bailliére et Fils, 1893. Price 
3fr. 50c. 
Tue French people are happy in the possession of a popular scientific 
literature of excellent quality and moderate price, of which they are 
justly to be envied. They produce books now and then, however, of 
which no nation envies them, and this is one. In the matter of bad 
popular books on fungi and lichens this country might be thought- 
lessly considered to hold the record, but it is refreshing to know that 
while our neighbours can beat us easily in serious research on these 
subjects, they can also show us the way in the matter of poor pro- 
ductions. It is almost enough to say of this little popular book on 
the study of lichens that its benighted author rejects Schwendener’s 
great discovery of the dual nature of lichens, and the symbiotic 
phenomena they illustrate. It ishardto do more than prove a matter, 
and after the establishment of this great fact by the researches of 
De Bary, Schwendener, Stahl, Bornet, and others, it was confidently 
expected that the old lichenological school would die out. It is dying, 
however, like a vested interest, and the patent rights in “‘ homzo- 
gonidisme”’ have been leased afresh by M. Acloque. His little book 
shows a most superficial knowledge of morphology in general, and the 
text is not much better than the figures, which are all that is not to 
be desired. 
NAKED-Eyve Botany. By F. E. Kitchener, M.A., F.L.S. [Beginners’ Text-Books 
of Science.] Small 8vo. Pp. xii. and 182. London: Percival & Co., 1892. 
Price 2s. 6d. net. 
THE series of elementary science text-books of which this is the 
first, has been projected to meet the want, long-felt, of something 
which will cover the ground of a few terms’ lectures and serve the. 
pupils as a supplement to those lectures. The volume comprises 
48 lessons, which may “be got up by the pupil by himself as prepared 
work,” or ‘taken in school unprepared with the help of a running 
commentary from the master in the form of a catechetical lecture.”’ 
These two objects are widely different, and demand very different 
treatment; with the help of a ‘‘ running commentary ” from a com- 
petent master the work before us may be of some use, but it is not 
one to put into the hands ofa beginner to ‘get up” alone. As lecture- 
skeletons on various types of flowers, the book may be a help to busy 
teachers, but they must be careful to explain crude statements and 
correct erroneous ones, such, for instance, as ‘‘ the leaf-stalk may be 
traced as carried on through the leaf to its apex, and sends out 
branches (or veins) on each side arranged like a feather,” the definition 
