22 Notes on Eydatina Senta. ['^jolnli.SH^^^ 
Yet tMs phenomena may be imitated with a common pendulum 
clock which has been stopped, and which can be set going by 
blowing the pendulum, and will appear self-sustaining afterwards. 
Of course this does not occasion any surprise, because we know 
that the power of gravity serves to keep the clock in motion. 
In time, by diligent research, the greater mystery will, doubt- 
less, be revealed to us. 
It will be worse than useless, nay, it will, as tending to retard 
inquiry, be mischievous to set down all the complex actions going 
on in organized beings as the result of a special vital force, until we 
are certain that it is hopeless to expect any further addition to our 
knowledge. Can we ever be certain of this ? What do we know 
of the power of electrical force, or the extent of its action ? 
We know that it will unite the inert elements of our atmo- 
sphere, and cause them to form the corrosive liquid nitric acid. 
We know, also, that it will rend asunder sodium and oxygen. It 
will cause an iron rod to expand, a muscle to contract. It is most 
improbable that we know the full extent of its action in the animal 
economy. 
A distinguished French philosopher, the Abbe Hauy, writes : — 
"Those specious causes and imaginary powers to which, in the 
Middle Ages, all natural phenomena, even those of an astronomical 
kind, were referred, but which, through the genius of Newton and 
Laplace, have been banished from the celestial spaces, have taken 
their last refuge in the recesses of organized beings, and from these 
retreats positive philosophy is preparing to expel them." 
Why are researches in this direction opposed, or regarded with 
prejudice ? As a result of them we may hope to arrive at the truth ; 
and surely, as an eloquent French preacher has said, the nearer we 
are to truth, the nearer we are to Grod. 
Y. — Notes on Eydatina Senta. By C. T. Hudson, LL.D. 
Plate XIX. 
There is so little known of the life-history of the Eotifers, and so 
many points of their structure remain unexplained, that it seems at 
first quite superfluous to notice any of their diseases ; and yet I 
am tempted to record the following facts, as they may prove in- 
teresting to those who are engaged in the same study as myself. 
In the beginning of February I found Hydatina Senta in 
tolerable abundance at Bedminster, in a large rain-puddle into 
which manure- water trickled. On returning a few days afterwards 
for some more specimens, I fished all round the puddle, and at 
different depths, in vain ; but in a hoof-print close to the puddle, and 
