SCIENTIFIC SOCIETIES, 255 
themselves. They would thus start on an independent course of variated 
history. Sundry other causes (both entrinsic and intrinsic) may determine 
this particular variation in the reproductive system ; and wherever it occurs 
it must give rise to a new species to record the fact. The proof of its 
occurrence is furnished both amongst our domesticated varieties and in 
nature. It explains the sterility between species, the frequent inutility of 
other specific characteristics, and entirely escapes the difficulty from inter- 
crossing. It therefore relieves the theory of Natural Selection from the 
disabilities under which it lies in consequence of having been improperly 
advanced as a theory of “the origin of species.” A discussion followed, in 
which Prof. Duncan, Mr. Breese, Mr. Dyer, Mr. Seebohm, the Rev. R. P. 
Murray, Mr. Michael, the President, and others, took part. 
The following technical paper was subsequently read in abstract, viz., 
“Descriptions of new species of Galerucide,” by Mr. Joseph S. Baly.— 
J. Morin. 
ZOOLOGICAL SociEry oF Lonpon. 
April 20.—Prof. W. H. Fiowrr, LL.D., F.R.S., President, in the chair. 
Mr. O. Salvin exhibited a living specimen of a foreign worm, Bipalium 
kewense, found in a garden in Sussex. 
The Secretary read an extract from a letter addressed by Mr. R. A. 
Sterndale to Sir Victor Brooke, concerning a case of hybridism between 
Ovis hodgsoni and O. vignei. 
Mr. J. Bland Sutton read a paper in which he gave an account of some 
of the investigations he had made during the past twelve months into the 
diseases affecting the Mammals living in the Society’s Collection. 
A communication was read from Dr. O. Finsch, describing a new species 
of Wild Pig from New Guinea, which he proposed to call Sus niger. 
Mr. Smith Woodward read a paper on the relations of the mandibular 
and hyoid arches in a Cretaceons Shark, Hybodus dubrisiensis, Mackie. 
A communication was read from Professor RB. Collett, of Christiana, 
containing an account of the hybrid between the Willow Grouse, 
Lagopus albus, and the Black Grouse, Tetrao tetrix, which occurs occa- 
sionally in Norway, Sweden, and Northern Russia, and of which the 
author had examined altogether thirteen Specimens, most of thei of the 
male sex. 
Mr. G. A. Boulenger gave the description of a new Iguanoid Lizard 
living in the Society’s Gardens, for which he proposed the name Ctenosaura 
erythromelas. The exact locality was unknown. 
A second paper by Mr. Boulenger contained remarks on specimens of it 
scarce Kuropean Frog, Rana arvalis, exhibited in the Society’s Menagerie. 
