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. 350) as probably contemporaneous 

 with the Crag of Norwich (Uppermost or Manimaliferous Crag), 

 indicate a rather shallow and cold sea (perhaps somewhat brack- 

 ish too) as their probable habitat. They are Pohjmorphina lactea, 

 Bulimina elegans, Truncatulina lohatula, Rotalia Beccarii, Poly- 

 stomella crispa, and P. striatopunctata. Mr. Prestwich's observa- 

 tions {loc. cit. p. 351) 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, Pohjmorphina, 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. Thury, of Genevaf. 

 M. Thury'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 " Resume," 

 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, during 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. 365), and Sir C. Lyell in 1839 (Mag. Nat. Hist, new series, 

 vol. ili. 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, iii- p. 556. 



t Translated by W. S. Dallas, F.L.S., from the abstract by Prof. Pjctet 

 in the ' Bibliotheque UniverscUe,' September 20, 1863, p. 91. 



