320 Miscellaneous. 



the two extremities, occur principally in the conjunctive tissue which 

 covers the branchial cavity. 



VASCULAR SYSTEM. 



Besides tlie large vessels so well described by Miiller, there is a 

 well-developed capillary system throughout the body. The capilla- 

 ries are met with iti the central nervous system and in the muscles ; 

 but it is especially at the anterior and posterior extremities of the 

 body, and in the delicate membrane which surrounds the body {i. e. 

 the fins), that they are most developed. These capillaries are very 

 delicate, transparent, and without nuclei in their walls ; they are 

 seen with difficulty when the body is covered with epithelium. In 

 the fins they assume a longitudinal direction, and show many sinuo- 

 sities and anastomoses. From the head to the tail they form around 

 the central nervous system and dorsal cord a series of longer or 

 shorter loops. They are met with in the interstices of the bundles 

 of the lateral muscles. Quatrefages thought he saw a movement of 

 blood in lacunae ; but these lacunae are capillaries with walls : they 

 are also found in the parts regarded by Miiller as the fin-rays, and 

 by Quatrefages as spinous apophyses, and it is in the opaque body 

 which these enclose that they are to be seen with the elastic fibres 

 and bodies of the conjunctive tissue. These capillaries are often 

 filled with small, round, regular, slightly granulated bodies T/l^,^th 

 millim. or less in diameter, and apparently destitute of a nucleus : 

 these are the blood-corpuscles of the Branchiostoma. I do not think 

 that they are visible in the living animal ; neither Miiller, nor Quatre- 

 fages, nor myself was able to see them therein. I found them in 

 specimens preserved in a solution of chromic acid. In any case, the 

 vascular system of the Lancelet is more complete than has hitherto 

 been supposed ; and the blood, with its corpuscles, is distributed 

 through it, as in other Vertebrata, in walled vessels, and not in 

 lacunae. 



EPITHELIUM. 



In the cells of the epithelium I could discover no nuclei. Thig 

 was the case also with Quatrefages. — Comptes Rendus, July 11, 1864. 



Note on the Great Auk, By Dr. P. L. Sclater, M.A., Sec. Z.S. 



With reference to the list by Mr. Champley, in a recent Number 

 of the ' Annals,' of the existing specimens of the skins and eggs of the 

 Great Auk {Alca impennis), my friend Dr. G. Hartlaub, of Bremen, 

 remarks to me, in a letter recently received, that it seems to be very 

 incomplete. Dr. Hartlaub states that there is a very beautiful spe- 

 cimen of this bird in the Bremen Museum, also one at Leyden, — 

 neither of which appear to be alluded to by Mr. Champley. 



The Oldenburg collection is also in possession of one of the finest 

 existing eggs of the Bird, which was acquired at the sale of the col- 

 lection of the late Dr. Graba, of Kiel, for little more than a thaler ! 



