188 
BRIGHTWELL, ON NOCTILUC^. 
tion of any process of this kind ; but in many individuals 
lie lias observed the yellow,, clear globules^ with a central^ 
well-defined nucleus^ more or less developed^ of a rich red- 
dish hue described by the above authors^ and deemed^ if 
not proved^ by the latter^ to be germs of NoctiluCce. (See 
Gosse, pi. xvi^ fig. 10.) 
When irritated^ the Noctilucse give out a phosphorescent 
lights which under a high magnifying power presents points 
of light more intense than the general glow. In captivity 
they soon lose this power. 
Little has hitherto been said as to the food of the Noctilucse^ 
and it will^ we think^ surprise some of our readers^ to find 
that these animals^ small as they are^ are sustained by 
Diatomacese^ and that, in these microphagists, we have the 
means of supplying our cabinets with specimens of some of 
our rarer diatoms. 
Colonel Baddeley observes that he finds, when newly 
gathered, each Noctiluca has several diatoms in its interior, 
lying in the various chambers or gastric pouches distributed 
throughout the body of the animal. These diatoms all dis- 
appear in a few days, leaving nothing visible but the vacuoles, 
or alimentary sacs, filled with granular particles. A very 
careful pressure shows an orifice, near the tail of the animal, 
the opening of v/hich may be detected by careful pressing, 
and from this is protruded, by continuous gentle pressure, a 
very thin hyaline sac, filling gradually with fluid and small 
globular particles, till it attains about one third the size of 
the animal, when it bursts and disappears. On a greater 
pressure being applied, the so-called mouth, together with 
the thread-like walls (the netAvork of fibres and fibrils of 
Mr. Huxley), shoot out through the opening, and float away. 
In a paper published by Mr. Huxley in the Annals Nat. 
Hist.^ (vol. viii, new series, p. 433), on Thalassicolla, he states 
that its structure is essentially similar to that of Noctiluca, 
and that there is a perfect analogy between the structure of 
his Thalassicolla nucleata and ActinopJwys Sol. He defines 
the latter, ^' sl spherical gelatinous mass, consisting of an in- 
ternal dark granular portion, and a clearer external zone, from 
which many radiating threads are given off". Vacuole are 
scattered through the substance, larger in the external zone, 
smaller and more irregular in the interior. If the animal is 
much compressed nuclei and nucleated cells are forced out 
from its interior.^^ Mr. Huxley, in this paper, intimates his 
opinion that, in the case of Actinophrys sol and Noctilucse, 
no spontaneous fission takes place, but that two individuals 
may fuse together and' become one. 
In 1848, 1 stated, from my own observations, that Act. Sol 
