352 
POPULAR SCIENCE REVIEW. 
was composed of the mixture of the red atoms and gelatinous excretion. 
One. infant rotifer/ whose first efforts at building he had distinctly marked, 
seemed to have made his entire nest of the glowing pigment. — Vide 
Transactions of the Microscopical Society, No. 26. 
A curious larva has been described to the Dublin Microscopical Club, by 
Mr. John Barker. It was found in boggy ground in the Co. Wicklow. As we 
have ourselves met this interesting form in large colonies, in some of the 
Irish bogs we give the description of it for our entomological readers. The 
larva was in great part enveloped in a compressed quadrangular case, expand- 
ing towards the posterior end, elliptic in section j the aperture elliptic, 
semi- trumpet-shaped, everted and a little flattened. Through this the 
larva protruded its head and three pair of legs, which were long and, with 
the exception of the first pair, which were short and ended in a forceps, 
were armed with long and slightly curved unequal hooks. By means of 
its legs the creature crawled along the bottom and sides of the vessel, 
carrying the case swinging obliquely above. The two valve -like sides of 
the case approximated towards the base, so as to present a slit ; it seemed 
composed of structureless chitine, with a few hairs on its surface. It was 
about in length, and I*/' broad at the base. The larva, after it had been 
in confinement about a fortnight, anchored itself . by a sort of byssus to the 
sides of the vessel. First, a mucous substance was deposited on the glass at 
four different points ; then four sets of cords (about fifty in each) united 
these attachments, two to the long axis of the mouth of the case, and two to 
the angles of the base. The animal lay much shortened, with its head 
curved round, its legs close together, entirely within the case. 
The animal nature of sponges is demonstrated very clearly in a paper by 
Prof. H. J. Clark, in a late number of Silliman’s American Journal. The 
American naturalist considers that the ciliated sponges are most closely 
allied to the monociliate Infusoria flag ellata. 
How to observe the reproduction of Zoophytes. — Dr. T. Strethill Wright, in 
a paper on u British Zoophytes,” gives some valuable advice to those who 
wish to study the mode of reproduction of zoophytes. His remarks have 
especial reference to the Naked-eyed Medusce. He says that the greatest 
care must be taken that the sea- water used in the experiment is perfectly 
free from the presence of the planuloid larvae of other forms, which are 
frequently contained in water recently brought from the sea. The water 
must be slowly passed through filtering paper into a glass vessel capable of 
containing not less than three or four gallons, in which are placed a few 
fronds of Chondrus crispus or Enteromorpha. A few of the medusae only should 
be placed in the vessel, amongst which it is advisable, but not necessary, that 
one should be a male with white and opaque, not transparent, spermatic sacs. 
The animals should be frequently fed with minute pieces of mussel or oyster. 
As soon as the planulae appear they should be removed with a dipping- 
tube into a round glass shade inverted and filled with sea-water from the 
larger vessel, to which a few drops of mussel-juice must be added daily until 
it appears crowded with minute protozoa to serve as food for the future 
hydroids. The internal surface of the shade, and the surface of the water, 
should be examined often from without with an inch lens, and as soon as 
each planula adheres to the inside of the glass, a thin disc of microscopic 
