146 
THE YOUNG SCIENTIST. 
which proceed two cilia, and it is the mo- 
tion of these cilia that cause the globes to 
roll through the water. In the interior of 
the Volvox may be seen from two to twenty- 
smaller globes, and sometimes these small 
globes contain others still more minute. 
After a time the small globes escape from the 
parent globe, and pursue an independent 
existence, after which the parent dies. 
It is not many years since the Volvox was 
considered quite a rarity in this country, 
and many good microscopists believed that 
it was not to be found in American waters. 
The writer has a distinct impression that he 
VOLVOX GLOBATOR. 
was told by the late Dr. Goadby, who was 
quite familiar with it in England, and had 
traveled extensively in this country, that 
he had never met the Volvox in America, 
and yet Goadby was quite familiar with the 
microscopic inhabitants of our ponds. At 
any rate it is but a few years since the 
writer himself first saw it and published the 
fact, but since that time it has been fre- 
quently discovered in localities in which it 
was not supposed to have been previously 
found. It must be remembered, however, 
that the Volvox is very apt to escape the ob- 
servation of those who are not familiar with 
it, and yet, like the well-known puzzle pic- 
tures, when once seen it is ever afterwards 
quite obvious when present. Evidence of 
the truth of this statement is found in the 
fact that while the ponds around London 
have always been famous for Volvox, Baker, 
at the time of writing the first edition of 
his book, "Employment for the Micro- 
scope," (1753) had never found them him- 
self, and wrote his description from speci- 
mens accidentally found in water sent to 
him from Yarmouth by a friend. 
The Volvox is generally found in clear 
still water, free from such filth as sewage 
and decaying animal matter. The clear, 
open spaces amongst water plants are 
always likely places. We have found it in 
ponds densely shaded by trees, and also in 
those that were entirely exposed. 
In searching for the Volvox and similar 
organisms, we have found the best instru- 
ment to be a clean homoeopathic phial of 
good size — say half an ounce. Such a phial 
may be fastened to the end of a cane by 
means of the cheap little device shown on 
page 131 of " How to Use the Microscope." 
A dip " may then be taken from any clear 
pool, the bottle removed from its holder, 
wiped dry on the outside, and examined 
with a half -inch lens. The Volvox, if pres- 
ent, will be seen as a pale-green globe, roll- 
ing about in the water and having little 
specks in its inside. In order to cause all 
the water to pass before the lens, it is well 
to give the bottle a slight whirl. 
Under a power of twenty-five to fifty 
diameters, such as can be had from any 
cheap microscope, the Volvox presents a 
most beautiful and interesting appearance. 
To examine its ultimate structure requires 
good instruments, but its general form and 
its beautiful movements may be seen by 
means of a little French stand costing $2.50. 
The Heavens for November. 
BY BEKIilN H. WRIGHT. 
THE computations in the following are 
made for the meridian of New York 
city, and are expressed in mean or clock 
time: 
The Superior Planets — How to Find Them, 
and their Telescopic Appearance and Epher- 
merides. — Mars is an object of great inter- 
est, both to the practical astronomer and 
the amateur observer. His surface has 
been more closely studied than that of any 
other planet, and though 51,000,000 miles 
distant, the natural divisions of its surface 
are accurately mapped and named. Thus 
Herschel Continent, Cassini Land, Hind 
Peninsula, Phillip's Island, Delure Ocean, 
Delambert Sea and Arago Strait, are among 
the natural divisions given in our Martial 
geography. 
A telescope of two-inch aperture will 
give fair views of the continental mark- 
