203 
[Fewkes. 
generally considered, and the same is possibly true of the peculiar 
nematoc} T st-like bodies on the outer surface of the bell of genera 
like Gemmaria and Willia. In Athorybia also, the rows of so-called 
nematocysts on the outer walls of the covering-scales do not in many 
cases show the “fil d’un nematocyste,” and therefore we may well 
question whether they are functionally nematocysts, lacking as they 
do this characteristic internal organization of these organs. Still 
the homology of these structures to nematocysts is an open ques- 
tion and it remains yet to be seen whether they might not be re- 
garded as lasso-cells in which certain parts have suffered a change 
in form. 
There seems nothing to prevent our accepting the theory that the 
“corps spheriques” of the above description are homologues of 
nematoc}’sts, and Bedot’s figure as far as it goes does not disprove 
that they are these organs even if the central “thread” is absent. 
Between these spherical bodies, however, and the pigment pouches 
or glands, Bedot thinks it necessary to recognize a distinction and 
certainly their form is very different, and justifies his views in this 
regard. Moreover the pigment glands discharge their contents, 
whereas the spherical bodies do not have this power. Is there, how- 
ever, anything to show that the pigment glands are not more com- 
pletely developed clusters of the so-called spherical bodies, and may 
not the pigment gland be formed by an aggregation and matura- 
tion of the spherical bodies ? Such an interpretation was given the 
colored bodies, when I studied them, and there is no new evidence 
to lead me to abandon my former opinion. The “pigment spots” 
were at that time regarded as remotely represented in Apolemia 
“by elevations composed of clusters of cells on the surface of the 
tract.” My use of the word cell with two meanings, one as a las- 
so-cell, and the other as a histological cell, has led to a confusion, 
and a just criticism by Bedot. I consider the pigment glands to 
be formed of an aggregation of nucleated cells, and each pigment 
spot to be comparable with a nematocyst (lasso-cell). 
In some genera, irritation of the animal leads to a change in color 
of the covering-scale which may be akin to the discharge of pigment 
from these bodies. This phenomenon seems also to be connected 
with pigment cells in the organs, although the character of these 
structures has not been fully described. 
Dr. Carl Chun mentions a change of color of the covering-scales 
in Ceratocymba spectabilis from the Canaries. He speaks of this 
phenomenon in the following manner : 
