eos SOME NEW BOOKS. 385 
agriculturist is that the interstices of the soil must be filled with air, 
and not saturated with water like a sponge. 
Chapter II. deals with food obtained by the plant from soil, and 
is excellent as far as it goes, the student being taught that soluble 
substances only can pass into the roots, and that there are certain 
substances in the soil, soluble in water, which are absorbed by the 
roots for food, but no reference is made to the greatly increased 
power of solution afforded by the acid reaction of the root-hairs, or 
the carbonic acid gas dissolved in rain-water. 
The nature of the soil, the “‘ substances of a leaf,’ the composi- 
tion of the air, and the absorption of carbonaceous food therefrom, 
are well explained, though surely in the heading on p. 4o, ‘‘The 
Seed obtains Food from the Air,” we should read Seedling for Seed. 
In the seventh and last chapter, on the source of the nitrogen 
required by plants, the author is a little too crude and brief in his 
explanation of nitrification and the tubercles on the roots of legu- 
minous plants, ‘full of minute creatures, to which the name of 
bacteria have (sic) been given.” The two appendices ‘ Notes on the 
Experiments,” and “On the use of the balance,” contain useful hints. 
Mr. Laurie should have got a botanical friend to look over his 
proofs, and thus have avoided the serious errors which mar what 
might have been a capital little book. 
PrECIS DE TERATOLOGIE, ANOMALIES ET MONSTRUOSITES CHEZ L' HOMME ET CHEZ 
LES Animaux. Par L. Guinard, Chef des Travaux de Physiologie a l’Ecole 
vétérinaire de Lyon. Précedé d’une préface par M. le Dr. Camille Dareste. 
Pp. 512. With 272 figures. Paris: J. B. Bailliére et Fils, 1893. Price 8 francs. 
Arter the great work of Is. Geoffroy-Saint-Hilaire, published from 
1832-1837, for many years there was little done in Teratology. A few 
isolated papers contained descriptions of unusual monsters, but the 
attention of naturalists was so absorbed by the new light thrown on 
the domain of normal Nature that her freaks and sports were almost 
disregarded. Then, in quite recent years, came Camiile Dareste’s 
series of studies on the artificial production of monsters, and a number 
of other studies of which Mr. J. A. Thomson gave an interesting 
vésumé in the last number of NaTuRAL SciENCE.' The more recent 
part of the study of monsters concerns itself with the conditions of 
their production, and has been called by Dareste Teratogeny, as dis- 
tinguished from Teratology, the record and classification of the types. 
The present volume is limited designedly to Teratology, and is 
meant to be a compact and convenient guide to the known types of 
abnormality ; for, if it be, at the first glance, a paradox to write of 
types of abnormality, or to discuss the laws of disorder, a very brief 
study of M. Guinard’s volume will convince that monsters are not 
the frolic of chance, but an inverted or tip-tilted regularity. Some 
are caused by mere mechanical pressure or torsion, and cause and 
effect tread on each other’s heels as closely as the pressure of a boot 
and the growth of a corn; in others unusual condition, raising or 
lowering the temperature beyond the eurythermal limits, alteration 
of the natural position, conditions of strain (as on a centifrugal 
machine) tend to produce abnormalities, although the nexus of cause 
and effect is invisible; but, however produced, the productions fall 
readily into categories. M. Guinard gives, in a series of chapters, 
accounts of simple anomalies, classified according to the organs or 
1 NATURAL SCIENCE, vol. ii., pp. 294-306. 
PXS: 
