THE AQUARIUM, OCTOBER, 1892. 7 
When you have removed a cad from his 
case, if you throw him into an aqua- 
rium tank you will learn in an instant 
what is the use of his case, for his soft 
nakedness is no sooner exposed, than 
the minnows finish him, and find the 
flavor excellent. But to seeacad in his 
proper uniform molested is a very rare 
sight indeed. When he feels the numb- 
ness of death creeping over him, the 
cad draws in his six legs, and sets to 
work inside to weave a winding sheet 
and to shut the shutter, for he knows 
that his time is come, and there is no 
one to do such melancholy offices for 
him. All alone in his solitary cell, the 
hermit works day and night, and 
hourly his fingers grow more feeble. 
We look and find the shutters closed, 
and by this time the larvae has changed 
into a pupa. 
The mode in which the worm closes 
its cell is curious enough. Over its 
entrance it weaves a grating of silk, 
which hardens in water and remains 
insoluble. It may be seen very plainly 
by the naked eye, but under a good 
lens increases in interest. The grating 
is placed a little inside the margin of 
the opening, and fits exactly within it, 
and its object is to protect the pupa 
from invasion, and at the same time to 
admit water for respiration. 
But the escape of the pupa when 
about to undergo its last metamorpho- 
sis is as interesting as the fact of 
closing the shutters to announce its 
own death. Itis provided witha pair of 
hooked mandibles, with which to gnaw 
through the grating, and no sooner 
have these accomplished their purpose 
than they fall off, and the pupa takes 
its last shape of a four-winged fly, as 
represented in the cut. 
S: o. 
THE FANWORT. (Caboméa.) 
Fourteen years ago we received in a 
letter from one of our correspondents 
in the State of Louisiana, a sprig of a 
green water plant. In the letter the 
writer stated that in his rambles about 
the wild swamps he ran across a little 
pool in which he found this plant grow- 
ing. Ashe had an aquarium at home 
he gathered some of it to plant in his 
tank. Here it was much admired, but 
nobody seemed to have ever seen this 
variety of water plant before and he 
therefore concluded to send it to us in 
order to find out its name. 
As it was in winter season, the plant, 
or rather the sprig of it, was not in 
bloom and we were not able to analyze 
it to a certainty. We, however, sup- 
posed it to be a variety of Ranunculus 
aquatilis. (See illustration. ) 
The sprig in question received its 
proper care, and with the approach of 
the warmer weather it formed flower 
buds, then differently shaped leaves, 
and finally it bloomed. We recognized 
it now as a member of the water- 
shield family—Cabombacea ( (ray). 
An English work on botany which we 
consulted had a very correct illustration 
of it and gave Brazil as its home, but 
nothing else was said about it. 
The plant proved a valuable acquisi- 
tion to our collection of aquarium 
plants. Everybody who saw it wanted 
to buy it. As a matter of course we 
wrote to our correspondent in the South 
for more, but he was unable to find the 
pool again from which he had obtained 
it, and had even lost all that he had had 
in his own aquarium. We then wrote 
to different parts of the South, but for 
a long while without success. In the 
meanwhile, we propagated our stock 
from cuttings. 
