258 
can become attached in this manner uniess there are external brood- 
pouches. I have seen no evidence in support of the latter view.^ 
As we see from the description above, Stuckey has only observed 
one specimen the young of which had already left their brood-pouch. 
In faet this species has formed only a single brood-pouch consisting 
of a circular invagination around the column in its lower half. Al¬ 
ready in younger individuals there are sometimes a distinet circular 
Wall in the above named place (textfig. 52). A longitudinal section 
of the column wall in this place shows that we have to do with a 
circular, though as yet rather shallow, invagination (textfig. 48). The 
invagination contains no embryos. In a more advanced State the 
circular brood-pouch is considerably enlarged and reaches below 
the actinopharynx. In the sectioned specimen the brood-pouch 
contained several embryos not having developed their tentacles. 
In textfigure 53 I have reproduced a transversal hand-section of 
the animal showing the under part of the brood-pouch (b). The 
section is somewhat oblique as the brood-pouch seems narrower on 
the left side. The embryos are taken away. The textfigure 49 shows 
a longitudinal section through the upper part of the brood-pouch 
in this specimen (B: brood-pouch, c: column, m: mesenteries, x: 
communication between the outer medium and the brood-pouch). 
As long as the embryos are small, both rims of the brood-pouch 
are closely pressed together, when the embryos grow they emigrate 
from the brood-pouch and attach themselves in the expanded outer 
part of the brood-pouch. In this stadium the embryos seem to stand 
in a circular furrow around the animal (textfig. 50). From here they 
emigrate to the column wall (textfig. 51). 
The occurrence of an outer brood-pouch here from a locality 
about 34® 25 S may somewhat modify our apprehension of the 
causes to the origin of brood-pouches. I cannot here discuss this 
question. 
It is this species which is mentioned by Dr. Mortensen in 
his paper “Observations on protective adaptions and habits, mainly 
in marine animals“ (Vid. Medd. D. Naturh. Foren. Bd. 69. p. 83) as 
an instance of protective resemblance in an Actinian. It is stated 
to resemble the peculiar branches of the alga, on which it lives, 
to such a degree that it was very hard to distinguish. 
