88 Discolored Waters of the Gulf of California, | February, 
expansion of the body-covering would be by an imbibition of 
water from the outside, and a rupture would as Pa occur in one 
place as in another in such a case. 
- When confined in a drop of water, or in an animalcula cage, 
the little animals never lived as long as a minute, the field of vis- 
ion was often strewn with their remains before the observer had 
time to look through the tube of the microscope. This was espe- 
cially the case if some time had elapsed since their removal from 
the sea. When kept ina bucket or in any vessel containing a 
large quantity of water they lived for a much longer time. 
Many experiments were made with destructive agents with the 
view of killing the animalcule before they had time to destroy 
themselves, but the results were unsatisfactory. In every instance 
they failed to accomplish the end for which they were used; if 
they served any purpose it was to accelerate the process of self- 
destruction. 
The only explanation that I can give for this suicidal propen- 
sity lies in the abstraction of oxygen from the water; yet this 
appears somewhat exceptional in view of the fact that this gas is 
rather immaterial to the existence of the low, structureless forms 
of animal life. The bacteria, for instance, will flourish in infusions 
that have been boiled and hermetically sealed. 
We have a record of these minute animals having been in this 
locality for more than three hundred years, defying the combined 
action of the winds, waves, and currents, and remaining as closely — 
aggregated as a community of individuals endowed with reason 
or instinct, and not exposed to dispersing causes. They appar- — 
ently have great control over their movements, at least so far as ; 
regards the fixity of their positions. 4 
The great Colorado River, at the head of the gulf, constantly 
pours into it an immense volume of water which has a tendency — 
to carry things seaward, as it does logs and other drift; yet here 
is this microscopic animal, the 1-1000 of an inch long, exposed — 
to the same influence, but remaining in its chosen locality for 
centuries. What keeps these masses together forever in one 
place in spite of the circulation of the waters on the surface of 
the earth? Well might the question have presented itself to the 
_ mind of Darwin, but his meee imagination suggested no nee 
solution for it. 
-Other r patches of discolored water obey the same impulse 
