16 ANIMAL LIFE 
of abundance of individuals vastly outnumber all other 
animals, and which in point of importance in helping main- 
tain the complex and varied life of the ocean distinctly out- 
class all other marine forms. These animals are the marine 
Protozoa, those of the “ simplest animals ” which live in the 
ocean. 
Although the water at the surface of the ocean appears 
clear, and on superficial examination devoid of life, yet a 
drop of this water taken from certain ocean regions exam- 
ined under the microscope reveals the fact that this water 
is inhabited by Protozoa. Not only is the water at the 
very surface of the ocean the home of the simplest animals, 
but they can be found in all the water from the surface to 
a great depth beneath it. In a pint of this ocean water 
from the surface or near it there may be millions of these 
animals. In the oceans of the world the number of them 
is inconceivable. Dr. W. K. Brooks says that the “ basis 
of all the life in the modern ocean is found in the micro- 
organisms of the surface.” By micro-organisms he means 
the one-celled animals and the one-celled plants. For 
the simplest plants are, like the simplest animals, one- 
celled. “ Modern microscopical research,” he says, “has 
shown that these simple plants, and the Globigerine and 
Radiolaria [kinds of Protozoa] which feed upon them, are 
so abundant and prolific that they meet all demands and 
supply the food for all the animals of the ocean.” 
9. The Globigerine and Radiolaria—The Globigerine 
(Fig. 10) and Radiolaria (Fig. 11) are among the most in- 
teresting of all the simplest animals. Their simple one- 
celled body is surrounded by a microscopic shell, which 
among the Globigerine is usually made of lime (calcium 
carbonate), in the case of Radiolaria of silica. These minute 
shells present a great variety of shape and pattern, many 
being of the most exquisite symmetry and beauty. The 
shells are usually perforated by many small holes, through 
which project long, delicate, protoplasmic threads. These 
