Miscellaneous, 501 



aiialem, radii secundi et tertii dorsalis parte basali maculaque post- 

 operculari nigris. Squamis lin. long. 45, transv. 12 vel 13. D. 10 

 vel 11 ; A 14 vel 15. Longitudo tota 0*095 metri. 



In the whole structure of the body this species is very similar to 

 the preceding one, but it is considerably larger. The two species 

 might probably be distinguished, by the rounded, and not bilobed, 

 caudal fin, and the short dorsal fin, as a peculiar and readily recog- 

 nizable subgenus, from the rest of the Hemirhamphi ; for this the 

 name Dermatogenys {permogenys)y proposed by Kuhl and Van 

 Hasselt, might then be retained. 



Dr. Jagor took this last species upon the island of Samar, in the 

 Basey River, "with living young and fully developed ova," as stated 

 in the note appended to it, and as shown by the specimens. — Monats- 

 ber. Akad. Wiss. zu Berliuy March 1865, p. 132. 



On the Production of the Sexes. 

 By M. CosTE. 



In a former Number of the * Annals * (ser. 3. vol. xiii. p. 68) a transla- 

 tion was given of a remarkable paper by M. Thury, of Geneva^ upon 

 a supposed law of the production of the sexes in cattle. M. Thury 

 believes that* the ovum changes its sex as it becomes more and more 

 mature, being female at the commencement of the rutting-period, 

 and male towards its conclusion : hence, by permitting animals to 

 copulate only at the commencement or close of the rut, female or 

 male offspring ought to be procured. This, M. Thury says, has 

 been done in twenty-nine experiments made for the confirmation of 

 his hypothesis ; but M. Coste, whilst admitting the value of Thury's 

 observations, as probably calling attention to the direction in which 

 researches on this most interesting but difficult subject should be 

 pursued, states that his own researches have led him to conclusions 

 opposed to those of the Swiss physiologist. 



M. Coste denies that the descent of the ovum takes place at the 

 commencement of the rut, and that it is impregnated during this 

 descent, as assumed by M. Thury. He says that during this period 

 the ovum remains enclosed in its capsule, and that the rut ceases 

 with the descent of the ovum into the matrix. When this takes 

 place without fecundation, the ovum is abortive ; and the fecundation 

 takes place within the ovary, and whilst the ovum is still enclosed in 

 in its capsule. When female animals are opened two hours after 

 copulation, the spermatozoids are found moving among the fringes 

 of the vestibule and upon the surface of the ovary itself. Hence 

 the question is, whether the two degrees of maturation assumed by 

 M. Thury exist during the ovarian life of the ovum. 



Now the most mature ovum must be that of which the dehiscence 

 is imminent or has just taken place, and of which the germ, if not 

 at once impregnated, would perish immediately. According to 

 Thury, such an ovum should give a male product ; one which has 

 not attained to this limit of evolution should furnish a female pro- 

 duct. To test this hypothesis, birds (in which a single copulation 



Ann. ^ Mag, N, Hist. Ser. 3. Vol, xv. 34 



