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 Globigerinse and 

 Kadiolaria [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 Globigerinse and Radiolaria. The Globigerinas 

 (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 Globigerinae 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 



