228 
NOTICES OF BOOKS. 
Recherches anatomiques et physiologiques sur le Tradescantia virginica L. 
ar A. Gravis, Professeur 4 l’Université de Liége. Bruxelles: 
Hayez, 1898. 4to, pp. 804, tt. xxvii. 
Tse work before us belongs to a class of which there are too few 
examples. The author presents us with a strikingly complete struc- 
tural an phological graph (including imirably thorough 
account of development from the seed) of a single flowering plant—the 
well-known Tradescantia virginica—to which are added, here and there, 
interesting physiological observations. Current anatomical literature 
carried out, on special points ; and comprehensive works on single 
types among the vascular plants are nowadays rarely written, except 
in the case of isolated plants—mostly Pteridophytes—the details of 
wv = id to) d L 
Indeed, we know of only one anatomical monograph on a common 
plant carried out with anything like the completeness of the work 
before us, and that is the same author’s Recherches anatomiques sur 
les organes végétatifs de l’ Urtica dioica, published in 1885. The cause 
of the scarcity of this type of work lies on the surface. Interest is 
excited and reputations are made far more easily by conclusions, 
importance from the scientific point of view, but in reality this is 
y no means the case 
The object of pure descriptive anatomy is to enable us to con- 
shown by the same tissue in different plants. We cannot build : 
) without - 0. 
knowledge. To take a single instance, the phylogeny of the steles 
