REPORT ON THE CRINOIDEA. 407 
There is strong reason to believe that the “ovoid gland” of an Urchin or Starfish 
does not communicate with the exterior through the madreporite as described by 
Perrier, while there can now be no question respecting its direct connection with what 
has been generally described as the oral blood-vascular ring of these types. Koehler’s 
observations’ have demonstrated this connection in the Urchins, although it was 
categorically denied by Perrier.” It thus seems probable that although the “ ovoid 
gland” can no longer be described as a heart or even as a plexus of interlacing vessels, 
yet that it is a glandular structure interpolated in the blood-vascular system, and 
possibly one of the factories of the well known respiratory pigment of the Echinoderms. 
The following remarks by Welldon’ are noteworthy in connection with this subject :— 
“It is not too much to say that in every group of Invertebrates in which the vascular 
system has been at all carefully investigated, glandular appendages to the vessels have 
been found, which can, from their anatomical relations, have no other function than that 
of elaborating some of the constituents of the blood... .. In Echimoderms, the 
abundance of glandular cells in the cardiac plexus is probably a principal cause of 
the whole organ being regarded by many observers as an excretory apparatus.” 
NOTE G. 
(Page 119.) 
THE Nervous SYSTEM OF THE CRINOIDEA. 
Since the section on the nervous system was written (ante, pp. 111-127), the subject 
has been still further discussed by various morphologists, most of whom, I am glad to 
say, have adopted the views advanced therein, and have strengthened them very 
considerably. As in so many other cases, it appears that the doctrine of the nervous 
nature of the axial cords in the skeleton of a Crinoid is not of such recent growth as has 
been supposed. For the following passage from von Schlotheim* would seem to show 
that a nervous function was attributed to the contents of the central canal of the skeleton 
more than sixty years ago:—‘“ Da die Encriniten aber simmtlich mit einer durch alle 
Zweige laufenden Nervenrohre versehen sind, ud das Thier wenn es gleich mit der 
Wurzel angewachsen zu sein scheint, doch mit allen seinen festen Theilen beweglich 
bleibt, so gehért er offenbar nicht zu der Corallenarten, und macht nur ein merkwiir- 
diges Verbindungsglied zwischen der Classe der Crustaceen und der Zoophyten aus.” 
A general, and, on the whole, tolerably accurate account of the morphology of living 
Crinoids was published by Weinberg ° in the course of last year (1883). It is principally 
1 Op. cit., p. 65, pl. 3, fig. 13. 2 Archives de Zool. expér., vol. iv., 1875, p. 613. 
3 On the Head-Kidney of Bdellostoma, with a suggestion as to the origin of the Suprarenal Bodies, Quart. Journ. 
Mier. Sci., vol. xxiv., 1884, N. S., pp. 180, 181. 
+ Die Petrefactenkunde, Gotha, 1820, p. 327. 
5 Die Morphologie der lebenden Crinoideen mit Beziehung auf die Form Antedon rosacea, Linck, Der Naturhis- 
toriker, 5 Jahrg. Marz—Juni Heft, 1883, pp. 266-307. 
