149 
(/) A zone of pale bluish, rounded granules, in the 
middle of which is ( g ) a well-defined cell- membrane, con- 
taining numerous salmon-coloured or yellowish fatty globules 
of uniform size ( h ). 
Thalassicolla differs from Sphaerozoum and Collosphsera in 
the nucleus being at least commonly multiglobular, with a 
distinct cell investment, while they differ from it in possessing 
a pellicle, cell, shell, or spicules, external to or including the 
sarcoblasts. We find points of resemblance in the external 
gelatinous test, the vacuolated matrix, peripheral in Thalassi- 
colla, and central in the other forms ; in the radiating 
branched fibres and the sarcoblasts, the cell-wall immediately 
surrounded by these last, and its granular contents. More- 
over, the plastic matter in which the sarcoblasts are im- 
bedded in Sphaerozoum may represent the dark pigment of 
Thalassicolla nucleata. 
Though these simple forms of animal life may be stated to 
possess a nucleus, yet does this nucleus not only differ con- 
siderably in the two leading types above described, but it 
would appear to hold no relation to the nucleus of Amoeba, 
or the other better known Protozoa. 
As to the question of the simple or compound nature of 
the punctate forms, Dr. Wallich states that “isolated free 
floating individuals of the Sphaerozoum and Collosphaera type 
are constantly to be met with,” and are to be found “ not only 
as free floating organisms, but also within the digestive 
cavities of Hydrozoa, of far too minute size to have been able 
to swallow them in the aggregate state;” but anybody 
acquainted with the filmy and destructible nature of the 
connecting substance in some specimens would doubt much 
that those “ free floating individuals ” were not detached 
from a normally composite mass. My own experience quite 
accords with that of Dr. Wallich above quoted, but I must 
say that it would not warrant me to arrive at the same con- 
clusion. I rather incline to the belief that at least one 
mode of increase is by fission, as indicated by the dumb-bell- 
like, and moniliform character of the masses, so frequently 
observed. 1 have only to add to these remarks, that I have re- 
peatedly seen Thalassicolla nucleata give out a phosphorescent 
light on being irritated or pressed between tw r o slips of glass ; 
any argument, therefore, founded upon the assumed absence 
of this phosphorescence cannot be sound. 
