Jf6 The jYcdivrLilists^ Convpcmioit, 
Next to this collection of mound 
pipes, tlie Davenport (Town) Academy 
of NatnralScience possesses the largest 
series of such pipes in the world, which 
now numhers about sixty examples. 
A few years ago INIr. W. H. Pratt, one 
of the members of this Society, made 
inquiries as to how many other speci¬ 
mens were known in collections in the 
United States. He succeeded in find¬ 
ing, all told, onl}' about a dozen speci¬ 
mens, but since then several others 
have come to light and there ma}' now 
be as many as twenty on record, 
Mr. A. E. Douglass, of New York 
city, has probably the finest private 
collection of pipes in the United States, 
which includes several specimens of 
this form. Amongst others he pos¬ 
sesses a platform pipe with a bowl 
carved to resemble the head of a Kocky 
Mountain sheep, its peculiarity consist¬ 
ing in the fact that the head faces 
away from the smoker. This is the 
only specimen known which possesses 
this feature. In every other specimen 
thus far discovered the head of the 
animal, bird or human being faces 
toward the stem orifice. Platform, or 
curve-base pipes,as they are sometimes 
called, are the most valuable of all 
aboriginal pipes. 
Metamorphosis of Arachnida. 
BY “FRANCIS.”' 
“Do spiders undergo metamorpho¬ 
sis?” If this question were asked of 
the ordinary observers of Nature, the 
answer would probably be purely a 
Yankee one. “Who ever saw a spider 
in the form of a grub, change into a 
pupa, and finally transform into a web¬ 
spinning insect ?” Such a supposition 
savours to a certain extent of absurd¬ 
ity. But as a matter of fact, many of 
the Arachnida do pass through the 
stages of larva, nynqih, and perfect in¬ 
sect. In some genera the metamor¬ 
phosis is very niarkel, and in a few 
species even further change is super- 
added. 
Most of the Arachnida that do nob 
undergo metamorphosis, shed their 
skins from time to time, and internal 
changes go on before and after these 
moultings, which are very considerable 
and important. JMoult alter moult pro¬ 
duces fresh changes, and the appear¬ 
ance of new structures, so that finally 
the sum of all these alterations almost 
equals in amount those which the trans¬ 
forming spiders undergo. The non- 
transforming spiders, however, are 
hatched from the egg in a more perfect 
state of development. They are hatch¬ 
ed with four good pairs of legs, wdiile 
their relatives, that suffer metamor¬ 
phosis,have only the rudiments of three 
pairs when they emerge from the ovum. 
Most of our common spiders, so cal¬ 
led, simply pass through several moult¬ 
ings, each time changing essentially 
their general structure, and each time 
gaining in strength and activit3v Be¬ 
ing hatched with only imperfectly de¬ 
veloped limbs, and with onl^^ a limited 
amount of strength, they do not come 
to their full strength and vitality un¬ 
til their last moult has taken place. 
The spiders whicii undergo transfor¬ 
mation include the Acarida and the Hy- 
drachnidmj, or water mites; those curi¬ 
ous little spider-like insects that we see 
in such countless numbers on the sur¬ 
face of our pools. The eggs may easily 
be found by a careful examination of 
the surfaces of the rocks, in and near 
the water. 
