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 Lichens. By A. Acloque. [Bibliotheque Scientifique Contemporaine.] 

 Pp. viii., 376. Illustrated. Paris : J. B. Bailliere et Fils, 1893. Price 

 3fr. 50c. 



The 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 is hard to 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 " homaeo- 

 gonidisme" have been leased afresh by M. Acloque. His httle 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-Eye Botany. By F. E. Kitchener. M.A., F.L.S. [Beginners' Text-Books 

 of Science.] Small 8vo. Pp. .\ii. 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 of a 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 



