140 P. HERBERT CARPENTER. 
admit that the results of their German colleagues, and more 
especially those of Ludwig, are in many respects very incor- 
rect; or else that the vascular system of an Urchin is far 
more different from that of a Starfish than has been hitherto 
supposed. 
The zoological group Echinodermata is so extremely well 
defined, and has so few direct relations with other classes of 
animals, that we are justified in expecting a close correspon- 
dence in fundamental characters among the different members of 
the group. Readers of this Journal will not need to be reminded 
of the detailed homologies which have been recently demon- 
strated in the Apical Systems of the three classes of Brachiate 
Echinoderms. The same may be said of the nervous system 
throughout all the Echinodermata, and, as I fully believe, of the 
vascular system too. But where one author tells us that the oral 
blood-vascular ring of a Starfish is in direct communication 
with an elaborate system of genital and visceral vessels beneath 
the dorsal surface, while another asserts that the correspond- 
ing structure in an Urchin communicates with the exterior 
through the madreporite, it is difficult to avoid the suspicion 
that further observations, conducted by the same method in 
both cases, may reveal an error somewhere. 
In the note to which I have referred allusion was made to a 
few points of this nature, in the hope that the authors con- 
cerned might take up the question again, so as to bring out 
more clearly the points of agreement or difference between 
them. 
Stimulated by my criticisms of what I, rightly or wrongly, 
conceived to be certain possibilities of error in Koehler’s treat- 
ment of his subject, he has returned to it again with the fol- 
lowing results! :—“ Quoiqu’il en soit de cette discussion, je 
ne puis que maintenir les résultats auxquels je suis arrivé. 
J’ai répété mes injections un assez grand nombre de fois vou- 
lant vérifier les faits que j’avancais, surtout au sujet des dis- 
positions sur lesquels Carpenter émet des doutes, pour croire 
1 ©Quelques mots sur les relations du Systeme circulatoire chez les 
Echinides,” ‘ Zool. Anzeiger,’ viii Jahrg., 1885, p. 83, 
