passes backwards beneath the cava, and, being joined by anasto- moses from the spinal artery, form the commencement of a vessel which the author formerly described in the ' Medical Gazette' as the subspinal vessel. This vessel, extending along the under surface of the nervous cord, communicates directly, by short vessels, with the supra-spinal artery, and gives off, at certain distances from its under surface, several large vessels, which unite with others that convey the blood which has circulated through the abdominal segments, di- rectly to the branchiae, whence it is returned to the heart by many minute vessels that originate from the posterior internal part of each branchia, and, united into single trunks, pass around the sides of the segments to the valvular openings on the dorsal surface of the heart. In the tail of the Scorpion there is a direct vascular communication between the caudal artery and the subspinal vein, which, from the direction of the vessels, induces a belief that there is some peculi- arity in the circulation of the blood in this part of the body. Be- sides these vessels, the author found an arterial trunk that originates from the commencement of the aorta as it descends into the thorax. This vessel passes backwards along the alimentary canal, to which it is distributed, and gives off branches to the liver.
This paper is accompanied by five drawings, illustrating the ana- tomical facts which are described in it.
The Society then adjourned over the Easter Recess to meet again on the 27th instant.
In consequence of the lamented death of H. R. H. the Duke of Sussex, the Society did not resume their Meetings till the 11th of May.
May 11, 1843.
The MARQUIS OF NORTHAMPTON, President, in the Chair.
George Basevi, Esq., and Colonel John Le Couteur, Avere balloted for, and duly elected into the Society.
Edward Speer, Esq., was also balloted for, but not elected into the Society.
The following papers were read, viz. —
1. "Variations de la Declinaison et Intensite Horizontale mag- netique observees a Milan pendant vingt-quatre heures consecu- tives le 22 et 23 Mars, et le 19 et 20 Avril 1843." Par F. Carlini, For.Mem.R.S.
2. " Note regarding the Observations of T. Wharton Jones, Esq., F.R.S., * On the Blood Corpuscles.' " By Martin Barrv, M.D., F.R.S. L.&E.
