146 
THE GUIDE TO NATURE 
with their eyes and ears. Walk with 
a painter, and he will teach you secrets 
of light and shadow that will trans- 
fuse your spirit with a mysterious and 
far-reaching beauty such as you never 
imagined before. Walk with a natu- 
ralist, and flowers and birds, which 
were mere blotches of color and 
snatches of song, will assume a signifi- 
cance, a charm, a life that will make 
you seem to have walked right into 
an undiscovered country. 
Walk with your feet by all means, 
even if you have to neglect your auto- 
mobile to do it. But at the same time 
open your eyes and ears, direct them, 
use them, and they will lead you into 
new worlds of inexhaustible delight. — 
The Youth’s Companion. 
A Natural Shark Trap. 
BY DAVID STARR JORDAN, STANFORD UNI- 
VERSITY, CALIFORNIA. 
In Southeastern Alaska is a curious 
natural shark trap, ultimately to be 
fitted with the teeth of these creatures, 
and which may help to explain certain 
deposits found in California and else- 
where in rocks of Miocene Age. 
The north end of Wrangel Island is 
indented by a peculiar little flask- 
shaped bay flooded deep at high tide 
but otherwise a mass of soft white mud, 
for it receives the glacial detritus (very 
fine clay) brought down by the iarge 
and swift Stikin River. Not far away 
stands a cannery from which tons of 
salmon heads and entrails are thrown 
into the sea. This offal attracts large 
numbers of the great sleeper shark, 
Somniosus microcephalus, a twenty-foot 
long, sluggish, greedy fish which 
gorges itself to repletion and then re- 
treats at high water to rest in the ad- 
jacent bay. Ebb tide leaves it helpless 
in the mud ; and during the course of 
a summer great numbers of sleepers 
and other sharks are thus destroyed. 
In the end, of course, the flesh decays, 
but teeth and occasional fin spines are 
preserved as fossils, so that when — 
centuries hence — the bay fills up and 
dries out, it should form a very inter- 
esting ground for collectors. 
In Kern County, California, a similar 
fine clay sediment scattered along the 
plains at the foot of the once glaciated 
Sierra carries enormous numbers of 
sharks’ teeth, especially of an extinct 
mackerel shark, Isurus hastalis, which 
must have been fifty feet long. With 
these appear occasionally the teeth of 
a still greater white shark, Carcharodon 
megalodon, much more than a hundred 
feet long — a veritable “man-eater,” al- 
though in those days there were no men 
for it to eat. Multitudes of teeth of 
smaller sharks and of sting rays also 
occur in these deposits which, I am in- 
clined to think, were probably laid 
down under conditions similar to those 
now observable at Wrangel. 
Starting Fern Spores. 
Fern spores, as everybody knows, 
are produced in great abundance, and 
yet new fern plants are not usually nu- 
merous. There are many vicissitudes 
in the life of a sporeling and few come 
to maturity. The spores are so exceed- 
ingly minute and the conditions for 
growth are necessarily so exacting that 
young plants are easily discouraged. 
Those who grow ferns from spores 
find that great care must be taken in 
preparing the soil. Usually it is steril- 
ized by baking and even then other low 
forms of life may overrun the young 
plants before they fairly get started in 
the world. Often the spores are sown 
on a block of peat which is kept moist 
and sheltered from the sun and wind. 
Noticing how frequently sporelings are 
found on the outside of the flowerpots 
in the greenhouse, some growers stop 
up the hole in the bottom of a pot, fill 
the pot with water and sow the spores 
on the outside. The water seeps 
through just fast enough to give the 
proper amount of moisture. 
An improvement on this method is to 
hollow out one side of a soft brick and 
fill the hollow with sterile soil upon 
which the spores are sown. The brick 
is then placed in a saucer of water and 
“kept close,” as the grower phrases it. 
This method of growing plants may 
also be followed in the case of minute 
seeds which are difficult to start in or- 
dinary seed pans or flats. — “The Amer- 
ican Botanist.” 
There are now in Florida eleven bird 
sanctuaries established by the Federal 
government, mostly islands. In addi- 
tion there are many others, private and 
municipal. The Federal sanctuaries in 
the entire United States now number 
seventy-three. 
