3840 E. W. MACBRIDE. 
filled up will become evident when I state in the first place, 
that my researches have made it clear that the Crinoids are 
only very distantly related to the other classes of Echinoderms, 
and secondly, that our previous knowledge of the metamorphosis 
of Asterids and their allies was confined principally to the 
changes which take place in their external form. 
It will be most convenient, I think, to give first a general 
account of the development, and then to point out how far the 
results of other workers have been confirmed, as by this means 
needless repetition will be avoided. 
Methods adopted. 
My material consisted of a large number of larve of all 
stages including those which had just completed the metamor- 
phosis, and of a considerable number of young adults varying 
from an age of about three weeks to several months from the 
metamorphosis. Of these the former, with the exception of two 
small collections made by myself in Plymouth, 1893, and Jersey, 
1894, were collected for me and preserved according to my 
directions by the authorities of the Naples Zoological Station ; 
the latter were obtained for me and preserved by myself during 
my stay in the Naples Station in 1892. I have to express my 
deep sense of my indebtedness to Prof. Dohrn for his kindness 
in meeting my wishes, and to Cav. Salv. Lo Bianco for the 
extreme care and attention with which he carried out my 
directions. 
All the stages were preserved in osmic acid, followed by 
14—24 hours in Miiller’s fluid, as this method had yielded me 
the best results in the case of Ophiurids. It makes the speci- 
mens exceedingly brittle, but at the same time gives the most 
excellent preservation of the minute histology; preserved in 
this manner the various tissues are differentiated as to their 
staining capacities, so that the sections look almost like coloured 
diagrams. 
On account of their brittleness, and in order to avoid 
shrinkage in the tissues, the larvee were embedded in celloidin, 
and the celloidin block subsequently embedded in paraffin. 
