1889.1 
205 
[Fewkes. 
Haeckel offers the following explanation of the phenomenon in 
Forskalia : “ The excretion of the pigment-masses and the darken- 
ing of the water by it have probably the same physiological func- 
tion as in the Cephalopoda — to protect the attacked animal from 
its persecutors, and facilitate the capture of food animals.” 
The character of the “cystons ” in a genus of Apolemidse called 
Dicymbia is described by Haeckel. Each “ cormidium ” or cluster 
of the stem is said to have in this genus a single deep red cyston 
and the secreted pigment is accumulated in a “head-like terminal 
expansion of the distal proboscis, and thrown out by a small ter- 
minal opening, the anus.” 
In Apolemia uvaria 1 which often reaches a great size I have re- 
peatedly observed the so called “ cystons” in specimens from Villa 
Franca. Haeckel simply mentions the fact that each cormidium 
of this genus has several cystons but gives no special description 
of them. 
The cystons of Apolemia are brick red in color and easily dis- 
tinguished from the remaining appendages of the cormidium. Their 
general relationship to the covering scales may be seen in my fig- 
ure of the axis of well known A. uvaria from the Mediterranean. 
I have not seen them discharge their excretions , 2 but the intensity of 
their color varies in different individuals and in different cormidia 
on the axis. Although I have repeatedly watched the well known 
“lana di mare,” Apolemia, I have never been fortunate enough to 
discover one which ejected coloring matter from these reddish bod- 
ies, and have not been able to produce it by an irritation of the ani- 
mals. 
There is a peculiarity in the tasters of the genus Nanomia, which 
would seem to have a bearing on the discussion of the pigmented 
bodies of the cystons. 
A. Agassiz, in his description of Nanomia, called attention to 
the pigment at the base of the taster of this genus, which he des- 
ignated as an “ oil-globule.” He supposed that this body formed 
the float of the young Nanomia which budded from the parent. 
1 The existence of what I have called “ Nectotasters ” or tentacular appendages to 
nectostem in Apolemia is not mentioned by Haeckel (op. cit.) although it is an excep- 
tional feature in Apolemia. These appendages and the stem which bears the necto- 
calyces of Apolemia are easily seen and have been figured and described. Kolliker 
speaks of them as the “ Fuhler zwischen den Schwimmglocken.” 
“Bull. Mus. Comp. Zool., Vol. vin, No. 7. 
