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by a curious accidental observation, viz. that by sucking the em¬ 
bryos up with a pipette and then squirting them out again with 
some force they were greatly assisted in rupturing the membrane 
and becoming free. 
A further interesting observation in this connection was made, 
viz. that those embryos which did not succeed in rupturing the 
egg membrane did not therefore die at once. On the contrary they 
continued developing further within the egg, the vibrat- 
ile bands and the yellow cells appearing at the same 
age as in the free embryos. In such cases the embryos accordingly 
reached the same stage within the egg membrane as do the em¬ 
bryos of Antedon mediterranea and bifida normally before they 
become free. If not liberated in the way mentioned above they 
gradually died away, but some of them remained alive even till 
the age of 6 days. 
Although excellent cultures of the larvæ were obtained repeat- 
edly both in 1918 and 1919 I never succeeded in rearing them 
through metamorphosis. About the time of the beginning formation 
of the vestibulary invagination they became abnormal, with a med¬ 
ian constriction or with the anterior end swollen as if hydrotropic. 
They might live for many days in this condition, but ultimately 
died without attaching themselves. Only in comparatively few cases 
did the vestibulary invagination develop normally, but even such 
larvæ did not attach themselves; a normal development of the 
Crinoid skeleton in the larva was not obtained either, only a few 
calcareous pieces were formed in some cases, which could not be 
identified with certainty. It could thus not be ascertained in this 
way, whether infrabasalia are present or not in this species. 
As it was thus found impossible to rear the larva through 
metamorphosis in the aquaria, I made some experiment to obtain 
the metamorphosis stages by putting the larvæ under more natural 
conditions. A sort of cage was made of silk gaze just close meshed 
enough to avoid the passage of the larvæ through the meshes. 
This cage, containing a good number of larvæ with some Bryozoa 
and Hydrozoa for eventual attachment, was sunk down to a depth 
of ca. 25 meters in the neighbourhood of the place where Antedon 
lives in about the same depth. After a week the cage was taken 
up and the content carefully examined. The result was not much 
