482 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The mouth soon forms an^ four tentacles make their appearance ; 
there does not seem to be any stomodajum, for the ectoderm and endoderm 
come into contact at the margin of the mouth-opening. Yogt has described 
the similar absence of a stomodaeum in a form which he calls Liplcea rus- 
poliana , but which is, probably, simply a Scyphistoma. Mesenteries are not 
formed till eight tentacles have been acquired ; this is a result at variance 
with the statement of Goette. 
Physiology of ‘ Portuguese Man-of-War.’ * — Mr. R. P. Bigelow has 
now published a more detailed account of his observations, a preliminary 
notice of which appeared last year.f Caravella maxima is an animal 
without any sense of sight, smell, or hearing, and with little or no sense 
of taste or touch. It has only a trace of co-ordination in its movements, 
in which there is a certain amount of rhythm, and every part is capable 
of originating an impulse. The only active part that it can take in its 
locomotion is to erect its sail when a breeze strikes it, or to heave to in 
a gale with its tentacles deeply extended into the water. If it rains, the 
float may be turned over so as to wash off the irritating fresh water. 
From a few observations made on specimens still in the warm water 
of the Gulf Stream, it is clear that in observing specimens taken near 
shore, some allowance must be made for debility. In the warmer waters 
the animals usually hold their crests erect ; the colours are much 
deeper and more brilliant than in the Woods Holl specimens, and the 
poison of the tentacles was very much more virulent ; the merest touch 
of the back of the finger to one of the tentacles produced the most 
intense pain. 
Four different fluids, at least, are secreted by Caravella ; the surface 
of the float is covered by a mucous secretion ; a very viscid fluid is 
secreted at the mouths of the siphons, by which they first attach them- 
selves to foreign bodies. The siphons secrete a digestive fluid, as is 
evident from the effect produced on food substances. The cnidocells 
secrete a poisonous fluid which produces a very painful sensation on the 
human skin, and causes a temporary ]3aralysis in a small animal, and in 
some cases death. The gas contained in tbe pneumatocyst is probably 
also a secretion. 
New Family of Hydroida.f — Prof. W. Baldwin Spencer proposes 
to establish a new family, that of the Hydroceratinidae, which he thus 
defines : — “ Hydrophyton consisting of a mass of entwined hydrorhiza, 
with a skeleton in the form of anastomosing chitinous tubes ; the surface 
is studded with tubular hydrothecae into which the hydranths can be 
completely retracted. Hydranths sessile, and connected with more than 
one hydrorhizal tube, claviform with a single verticil of filiform ten- 
tacles. Defensive zooids present, with a solid endodermal axis and 
nematocysts borne at the distal end.” 
This new family is established for a remarkable new form which is 
called ClatJirozoon Wilsoni, and which was obtained in Bass Straits, close 
to the Victorian shore, and at a depth of from 20-22 fms. It appears 
to be very rare. The largest colony measures 10 in. by 4, and at 
* John Hopkins Univ. Circ., x. (1891) pp. 90-3. 
t See this Journal, 1890, p. 467. 
i Trans. Koy. Soc. Victoria, 1890, pp. 121-9 (4 pis.). 
