199 



two Eyes." By T. Wharton Jones, Esq. Communicated by Ri- 

 chard Owen, Esq., F.K.S. 



The author animadverts on the doctrine which Mr. Wheatstone, 

 in his paper on the Physiology of Binocular vision, published in the 

 Philosophical Transactions for 1838, p. 371, has advanced, in oppo- 

 sition to the received theory of single vision being dependent on the 

 images of objects falhng on corresponding points of the two retinae. 

 He maintains that, under these circumstances, the two impressions 

 are not perceived by the mind at the same instant of time, but some- 

 times the one and sometimes the other. If one impression be much 

 stronger than the other, the former predominates over, or even ex> 

 eludes the other ; but still the appearance resulting from the predo- 

 minating image is nevertheless in some manner influenced by that 

 which is not perceived. He supposes that there are compartments 

 of the two retinae, having certain limits, of which any one point or 

 papilla of the one corresponds with any one point of the other, so 

 that impressions on them are not perceived separately ; and consi- 

 ders that this hypothesis, combined with the principle above stated, 

 is required, in order to explain the phenomena in question. 



February 6, 1840. 



JOHN WILLIAM LUBBOCK, Esq., V.P. and Treasurer, in the 



Chair. 



John Parkinson, Esq. and the Rev. Charles Pritchard, M.A, 

 were balloted for, and declared duly elected into the Society. 



A paper was read, entitled " Observations on the Blood-corpuscles 

 of certain species of the Genus Cervus." By George Gulliver, 

 Esq., F.R.S., Assistant Surgeon to the Royal Regiment of Horse 

 Guards. 



The author has found that the blood of the Muntjac*, the Por- 

 cine f, and the Mexican Deer J, contains, together with corpuscles 

 of the ordinary circular form, a still larger number of particles of 

 less regular shape; some curved and gibbous in the middle, and 

 acutely pointed at the ends, with a concave and convex margin, like 

 a crescent ; others approaching more nearly to segments of a circle ; 

 some shaped like a comma, being obtuse at one end and terminated 

 by a pointed curve at the other ; others having an acute projection of 

 the convex part, so as to constitute a triangular, or even quadrangular 

 outline ; some having the figure of the head of a lance ; while a few- 

 presented a double or sigmoid flexure, as if they had been twisted 

 half round at the middle. Like the ordinary blood-discs, these pe- 

 culiar corpuscles are deprived of their colouring matter by water ; 

 but with only a small quantity of water they quickly swell out, and 



* Cervus Reevesii, f C. Porcims^ I C. Mexicanus. 



