482 
SEITARO GOTO 
the existence of the endoderm lamella in Hydractinia echinata, 
but there cannot be the least doubt of its presence in the species 
we are considering^^ On a close examination of the figures repro- 
duced by Bunting2o there is hardly any doubt that the parts 
marked bn in figs. 6, 10, 11, 12, 13 are endoderm lamellae, although, 
strangely enough, nothing is said about them either in the text 
or in the explanation of figures. The lettering would suggest 
that she probably regarded them as parts of the bell-nucleus. 
Bunting and Goette must have missed the important stages. 
It must be remarked, however, that the endodermal lamellae are 
never more than one cell layer thick and no trace of canals is 
ever developed. In the stage represented in fig. 11 the ova still 
lie entirely in the endoderm, although some of them are in close 
contact with the supporting lamella. In a somewhat later stage, 
represented in fig. 12, the endodermal lamella is very distinct; 
nearly all the egg cells have passed out of the endoderm into the 
inner ectoderm and one is seen to be just passing through the sup- 
porting lamella, causing a big temporary hole in it. With the 
passing out of the egg cells from the endoderm of the bud a cavity 
becomes apparent in the latter, the endoderm cells assume an 
epithelial arrangement, and the lumen of the bud becomes con- 
tinuous with the gastric cavity of the blastostyle. The cells of 
the inner ectoderm have become scattered between the egg cells 
and between these and the supporting lamella; but they are as 
yet comparatively few. Another point that deserves notice in 
this stage is the eccentric position of the opening by which the 
outer ectoderm communicates with the inner. This condition 
occurs frequently, although it is not invariable, and the same 
can be found in many gonophore buds of a much younger age. 
At the stage represented in fig. 13 the gonophore has grown much 
larger, the endodermal lamella has become thinner, the spadix 
18 Bunting: '94, Colcutt: '98, Goette; "07. 
It appears to me that Agassiz ("60 and '62, pi. 16) shows in his fig. 8 the pres" 
ence of the endoderm lamella, marking it and calling it the "inner wall of 
the medusa." The figs, of Allman ('71, p. 32. and pi. 15, fig. 6) are not clear 
enough to enable one to say anything definite on this point. 
2° Bunting: '94, ])1. 18. 
