HOUSE AND GARDEN 
426 
Ju 
NE, I915 
winding in the same direction as the common garden snail. With 
a magnifying glass it could be seen that they were made of the 
finest grains of sand fitted together and forming this wonderful 
copy of a minute snail shell. 
Now these little structures had not simply grown like a flower 
in a mysterious manner which we hardly attempt to understand, 
but had been manufactured with mechanical skill which we would 
suppose must take years of experience to acquire. Yet each 
little caddis, about as soon as he was hatched, set to work to 
build himself this marvelous home without ever serving a day 
of apprenticeship. How is it done? We say by instinct; yet this 
takes nothing from the wonder of it nor offers any very satis¬ 
factory explanation. 
In the beautiful little stream 
flowing through Sleepy Hollow, 
within a stone’s throw of the old 
church which was made famous by 
Washington Irving, we found hun¬ 
dreds of little creatures, almost 
microscopic in dimensions, which 
had saved time and labor by crawl¬ 
ing into any little bit of hollow stem 
available, but, in compliance with 
the usual caddis habit, had loosely 
attached a few tiny fragments to 
the outer surface of their impro¬ 
vised cylinders. 
How it must have frightened the 
wary little creatures when those 
hoofs went thundering across the 
bridge over their heads in the dead 
of night, and they heard the hollow 
thud of that grewsome pumpkin 
as it was precipitated upon the 
cranium of poor Ichabod! 
But a New Yorker need not go 
to the Catskills or even to Sleepy 
Hollow to find caddis worms. 
Within sound of Broadway traffic 
and in sight of the Subway trains, 
above where they emerge from the 
tunnel, the little stonemasons may 
be found in abundance. In a spot 
no larger than a barrelhead fifty of 
one of the commoner varieties were 
counted, and it was here that we 
found one of the most interesting 
species. 
For lack of something better, let 
us compare it with a well-rounded oyster shell with the hollow 
side down and a cornucopia-shaped pocket on the under side. 
This little shell, only one-half of an inch in length and composed 
of the grains of sand from the bottom, over which it moves, is 
almost invisible. The inmate is particularly well protected, too, 
as he enjoys considerable freedom under his own canopy, coming 
out of the pocket nearly his full length and reaching about with¬ 
out appearing beyond the edge of the shell. When undisturbed 
he is much more active than any species I have observed, every 
move being quick and energetic. 
One individual, kept for a time under close observation, became 
sufficiently domesticated to relish little particles of lettuce leaves, 
but it must be confessed here that finally he was cruelly robbed 
of his house. It was needed for the camera. I thought he could 
probably build another; certainly I could not, but I did furnish 
him with the very best of material, nice, fine sand composed 
chiefly of water-worn grains of quartz, somewhat transparent, 
so that he might reveal his methods of constructing a home. 
The work was soon started by his burying himself just beneath 
the surface of the sand. With the microscope he could be seen 
through the quartz diligently “sewing” those grains together 
which immediately surrounded his head, thus forming a ring. 
Other grains were added to the forward edge of this ring, form¬ 
ing a slender cone, enlarging as he progressed. Soon he had come 
quite to the surface of the sand, so that the work could be watched 
more perfectly. The posterior end of the body now protruded 
only a little beyond the small end of the cone. Then the edges 
of the shell were begun, extending out on opposite sides of the 
cone and gradually widening until the pocket was completed. 
The curve of the shell was now 
continued forward and laterally, 
the workman reaching out for a 
grain of sand, then rolling over on 
his back to place it in position over 
his head. 
The work was carried on with 
great rapidity. Every grain seemed 
to be handled in nervous haste, 
with only an occasional pause, 
apparently for rest. Through the 
microscope each grain of sand, 
which, when compared with the 
worker, seemed like a stone or 
great rock, was picked up between 
the two front feet and tried in a 
certain space, turned over rapidly 
once or twice, and then end for end, 
until it could be made to fit. Fre¬ 
quently, when a fit was found quite 
impossible, not the stone, but the 
space, would be discarded for 
another. The stone, finally fitted, 
was then made fast with a few 
silk threads, and all this in a few 
seconds. The time spent in build¬ 
ing this structure, which was not 
so large as those shown in the illus¬ 
trations, was about six hours. The 
larger one of the two illustrated, 
it may be of interest to know, is 
made up of no less than fourteen 
hundred stones all fitted into place 
one by one. 
As a designer, I should say this 
species is among the most accom¬ 
plished, but in workmanship not 
equal to the simple stone cylinder maker. In the latter the stones 
are fitted much more perfectly and bound together with hundreds 
of silk threads, making a very strong structure, whereas the 
“oyster-shell” variety is so delicate that it must be handled with 
the greatest care. 
The larva is surprisingly small, as compared with the shell, 
being less than one-third its length and quite slender. Even the 
inner pocket is so spacious as to give the inmate almost room 
enough to run about, while with most species house and tenant 
make a pretty close fit. 
How strange that there should be such a diversity of taste 
shown among these kinsfolk, and what a world of craftsmanship 
is to be found within these narrow walls! Probably there are 
no labor troubles among these workers; every man his own 
employer; every shop a closed shop. But what an example of 
primitive individualism, walling one’s self into a stone cell, 
(Continued on page 454) 
Oak leaves skeletonized by the caddis worms and a beach leaf taken 
from the water during the operation. A caddis is shown on the 
lower border of the leaf, as it would appear in life 
