GAS QLANJDS OF SOME TELEOSTEAN FISHES. 191 



exists (described by Coggi, 26), compaxable in all essential respects 

 with that of the Cod. Also Vincent and Barnes, unlike many of 

 their predecessors, altogether fail to appreciate the peculiarity of 

 the arterial and venous nature of the rete mirabile ; indeed, they 

 even appear to have some doubt as to the fact itself. They say : 

 '' Corning has discriminated betwee'U arteries and veins in what 

 Ave have usually spoken of as the ' capillary masses.' This 

 he has done by means of a, sei'ies of injections. .... This method 

 would certainly give some idea of the distinction between the 

 smallest arterioles and smallest veTiules, but we are doubtful 

 whether it would be more than a. very rough method of distinc- 

 tion, that it would be, in any given case, an infallible test as to 

 whether a particular small vessel were to be called artery or vein. 

 Much would depend, it appears to us, on the strength of the 

 injecting force [!J. However this may be, we have failed to make 

 out anything in the minute structure which would warrant us in 

 dividing up the ' capillary masses ' into arterioles and venules." 

 This statement suggests that Vincent and Barnes never worked 

 through a series of sections of the Eel (or any other similar) 

 " red body " (which possibly also accounts for their missing the 

 gla,ndular epithelium of the Eel, which, as above stated, lies 

 separate from and posterior to the retia mirabilia *), since the 

 artei'ial and venous nature of the rete mirabilia is rendered quite 

 evident by this means alone ; also the last-quoted statement of 

 Vincent and Barnes is still less comprehensible when we remember 

 that these " red body " retia mirabilia have been correctly 

 described in full and compared with the several other kinds 

 of retia mirabilia which exist by Johannes Mliller (53) in 1840, 

 not to mention Owen's description (not confirmed by his figure, 

 however) of the " i-ed body " of the Eel just referred to f. 



(/ Vasculo-glandular Structures of the Anguilla or First Type in the 

 Bladders of some other Anguilliformes. 



Myrus vulgaris Kaup. 



In this physostome the vascular and glandular conditions are 

 similar to those found in Anguilla vtdgaris. The only essential 

 distinction between the two is in the character of the lining 

 epithelia of the duct and bladder, and in this particular the 



* A fact dearly stated hy Owen (' The Comparative Anatomy and Physiology of 

 Vertebrates,' vol. i. 1866, p. 495) : " The two chief ' retia mirabilia ' or vaso- 

 ganglions, in the air-bladder of the Eel and Conger, which are situated at the sides 

 of the opening of the air-duct, are also ' bipolar ' and consist of both arterioles and 

 venules [curiouslj' enough, however, in contradiction of this statement, the figure 

 329 of the ' vaso-ganglion ' of the Eel supplied on p. 496 shows the blood going 

 through all capillaries in one direction !] : they consist of straight parallel capillaries, 

 as in fig. 329 ; their afferent trunks do not ramify in the immediate margin of the 

 vaso-sanglion from which they issue, as in the vaso-ganglions of the Cod, Burbot, 

 Acerine, and Perch, but run for some distance before they again branch to form the 

 common capillary system of the lining membrane of the air-bladder." 



t These criticisms must not be held to imply any lack of appreciation of a very 

 lucid and interesting paper ; the fact, however, that the statements criticised have 

 been made use of by the late Professor Eridge so recently as 1904 shows the need for 

 correction. 



