Royal Society of Edinburgh. 121 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL SOCIETY OP EDINBURGH. 



This Society held its first ordinary meeting for the season on 

 Monday the 2nd of December, 1844. 



Read — 1. "Account of the late Earthquakes at Demerara." By 

 N. H. Campbell, Esq. Communicated by M. Pouton, Esq. 



2. " On the Existence of an Electrical Apparatus in the Flapper- 

 Skate and other Rays." By Dr. Stark. 



In this communication the author described a very peculiar organ, 

 which from its situation and structure he believed to be an electrical 

 organ. It ran along each side of the tail of the animal, forming 

 a large pad on each side of the lateral muscles. This organ was 

 much more developed in Raia Batis than in any of the other forms of 

 Ray, and less so in i2. clavata. The minute structure of the organ 

 was described as consisting of numerous septa running in the longi- 

 tudinal direction of the organ and forming cones, in the following 

 manner, with intermediate septa 

 running in an opposite direction. 

 The spaces within the smaller 

 septa were filled with a gelatinous 

 matter, which the author described 

 as similar to the gelatinous matter 



in the electrical organs of the torpedo and other electrical fivshes. The 

 nerves for the supply of these organs were derived from the eighth 

 pair or great lateral nerve, and the terminal filaments formed large 

 regular loops which were suspended in the gelatinous matter. 



Dec. 16. — 1. "On a possible Explanation of the Adaptation of the 

 Eye to Distinct Vision at diflTerent distances." By Professor Forbes. 



The author stated that the crystalline lens is loosely suspended 

 amidst the fluids of the eye, which are capable of conveying a uni- 

 form pressure to all parts of its surface. This pressure is the result 

 of the action of the recti muscles upon the exterior of the sclerotic 

 coat of the eye-ball, and is communicated to eveiy part of its con- 

 tents. The lens consists of a condensed nucleus surrounded exter- 

 nally by a softer and more gelatinous portion, so that the pressure 

 acting upon the softer and external parts diminishes the vertical dia- 

 meter of the lens, while that in the axis of vision may be increased, 

 thus increasing the curvature of the refracting surfaces and shortening 

 the focus. 



2. "Notice of an Ancient Beach near Stirling." By Charles 

 Maolaren, Esq. 



This beach consists of a terrace of stratified sand and gravel about 

 two miles in length, extending from the foot of Abbey Crag west- 

 ward to Lecropt Church. It is nearly level on the top, which is ele- 

 vated about 85 feet above the low alluvial plain called the Carse of 

 Stirling. Adding 20 or 25 feet for the height of this plain above the 

 Forth at Stirling, the elevation of the terrace above the level of high 

 tide will be about 110 feet. The breadth of the terrace is about 200 



Ann. 6f Mag. N. Hist. Vol. xv. K 



