584 JAMES F. GEMMILL 
in the axis of the directive mesenteries. Then the young 
anemones remain quiescent except in showing the following 
changes. 
1. Absorption of the trophenchyme within the archenteron. 
It is partly used up and partly absorbed into the endoderm 
layer, which becomes greatly thickened, as well as extended 
by the fuller growth of the mesenteries. 
2. Down-growth of stomodoeal ectoderm to form mesenteric 
filaments on the sulculo-lateral mesenteries. This began prior 
to fixation on the sulco-laterals. 
3. Formation of a new mesentery in each lateral and sulco- 
lateral Edwardsia space. These mesenteries can be detected 
near the middle of the column of the larva earlier than near 
the mouth or on the base. In my oldest specimens their 
developing muscle banners could with much difficulty be made 
out, each being formed on the sulcular side of its mesentery 
asin Urticina (1). They are thus suitably placed to form with 
the Kdwardsia sulco- and sulculo-laterals, the primary hexac- 
tinian ulco- and sulculo-lateral mesenteric pairs on each side, 
the rc maining pairs being of course the sulear and sulcular 
directives (fig. 15). 
[ tried to rear the young anemones further, but so far without 
success, although I gave the larvae the chance of settling down 
on shells, stones, glass, and mud, and of living after attachment 
either in separate hatching vessels, or in a tank with sea-water 
circulation. Those which settled on mud retained a rounded 
base, but otherwise reached much the same stages as the 
attached ones. None went the length of growing out tentacles. 
The attached specimens were less firmly fixed, and yet crept 
about less freely, than the corresponding stages in Urticina, 
in which also, as was shown by serial sections, the mesogloeal 
and muscular tissues were more strongly developed. 
For further comparative details and a discussion of some 
general problems connected with coelenterate development, 
reference may be made to a recent paper by the author in 
the *‘ Phil. Trans. Roy. Soc. Lond.’ (9) on the development 
of Metridium dianthus and Adamsia palliata. 
