NOTES ON ECHIXODERM MOEPEIOLOGY. 327 



''into diverging branches, of which one passes to each ray/' ^ 

 Some of these branches may, I believe, be readily made out in 

 optical sections of Pentacrinoids soon after the appearance of 

 the cirri ; but in most of the larvae which I have examined by 

 this or by the section method these branches have not yet 

 appeared, the axial organ ending close against the pharynx, 

 though in no way connected with it. 



The ramifying tubules which depend from the blood- vascular 

 ring of the adult, and form the labial plexus that unites this 

 ring and the axial organ (plexiform gland), do not seem to 

 develope until some time after the appearance of the cirri, for 

 I have seen no trace of them in any Pentacrinoid. The inter- 

 visceral vessels and those forming the genital plexus are also 

 late in development. But the latter seem to have been observed 

 by Perrier himself in the recently liberated Comatula. For 

 be says that within the meshes of the connective-tissue network 

 which occupies the body-cavity, there " courent un petit nombre 

 de cordons cellulaires pleins qui se rendent manifestement aux 

 bras/' Are not these a further development of the branches 

 from the axial organ, of which one passes to each ray, as 

 described by Dr. Carpenter? 



In conclusion, I would reiterate the hope which I expressed 

 in a previous note, that Professor Perrier will soon publish a 

 complete account of his views respecting the vascular system of 

 the Crinoids, both larval and adult ; and that he will illustrate 

 it by plenty of those figures which he knows so well how to 

 draw. The evidence which I have for the various statements 

 that have appeared in this journal will be given in some eight 

 or ten plates of the "Challenger" report. 



• ' Proc. Roy. Soc.,' vol. xxiv, p. 221. I can confirm this statement from 

 examination of the dissected larva on which it was founded. 



