68 Prof. Thury on the Law of the Production 
Southwold, and Bramerton) yields a Rhizopodal fauna somewhat 
similar to that of the Red Crag. 
The few kinds of Foraminifera yielded by the Chillesford Crag, 
a deposit regarded by Messrs. Wood and Prestwich (Quart. 
Journ. Geol. Soc. vol. v. p. 850) as probably contemporaneous 
with the Crag of Norwich (Uppermost or Mammaliferous Crag), 
indicate a rather shallow and cold sea (perhaps somewhat brack- 
ish too) as their probable habitat. They are Polymorphina lactea, 
Bulimina elegans, Truncatulina lobatula, Rotalia Beccarti, Poly- 
stomella crispa, and P. striatopunctata. Mr. Prestwich’s observa- 
tions (oc. cit. p. 851) on the probable influence of cold currents 
from the northern seas on the fossil fauna at Chillesford coincide 
with the above remarks. 
Lastly, some Foraminifera collected by H.C. Sorby, Esq., F.R.S., 
from the Bridlington Crag*, some years ago, and kindly lent to 
us, have to be noticed. These comprise Cornuspira, Miliola, 
Lagena, Dentalina, Cristellaria, Polymorphina, Cassidulina, 
Truncatulina, Polystomella, and Nonionina, and are the most 
conspicuous of a probably more extensive fauna, nearly allied to 
that of the Suffolk Crag. 
X.—On the Law of the Production of the Sexes in Plants, 
Animals, and Man. By Prof. Tuury, of Genevat. 
M. Tuury’s memoir is divided into three parts. In the first, 
entitled “ Deduction of the Law of the Sexes,” the author indi- 
cates the course of ideas which has led him to his theory. The 
second, which is shorter, contains, under the title of “ Résumé,” 
the complete exposition of the author’s notions. The third is a 
“Notice,” prepared by M. Cornaz, in which this clever agricul- 
turist describes the experiments which he has made, durmg two 
consecutive years, for the verification of the author’s theory, and 
by which the latter has been completely confirmed. 
The limits of this article do not allow of our following the 
author through the whole series of reasonings by which he 
establishes his theory. We shall only state that the study of 
plants, in which, by the management of the influence of external 
agents, the observer is enabled to instigate the development 
of either one or the other sex, seems to prove that the develop- 
* Mr. Bean wrote of the Bridlington Crag in 1835 (Mag. Nat. Hist. 
vol. viii. p. 355), and Sir C. Lyell in 1839 (Mag. Nat. Hist. new series, 
vol. iii. p. 313. See also Phillips’s ‘ Geol. Yorkshire,’ 1829, vol. i. p. 69 ; 
and H.C. Sorby’s paper on this Crag, in the ‘ Proceed. West Riding, 
Yorkshire, Geol. and Polytech. Soc.’ 1857, ii. p. 555. 
+ Translated by W. S. Dallas, F.L.S., from the abstract by Prof. Pictet 
in the ‘ Bibliothéque Universelle,’ September 20, 1863, p. 91. 
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