Attempt to Subordinate Protista to Cell-Theory 283 



bodies or intervals which separate them are very small. . . . 

 It is more in keeping with the laws of physics to admit that 

 in these small animals, liquids are taken in by simple im- 

 bibition; as it is more in keeping with rules established by 

 analogy not to assume that the plan of higher organisms 

 can be reproduced in these very small beings, since we see 

 the elements of these organisms, blood globules, muscle 

 fibers, and capillary vessels, instead of undergoing a pro- 

 gressive diminution in size in the smaller vertebrates, show- 

 ing almost the same size in the mouse and in the elephant." ^ 



In other words, the ph^^sical theory supported by certain 

 facts of structure and function in larger animals (rather 

 tlian any theory of organic evolution) led Dujardin to be- 

 lieve that such minute living beings as Infusorians must be 

 structureless and beyond question these tlieoretical views 

 largely influenced, and influenced harmfully, the results of 

 his observational studies. This fact deserves emphasis be- 

 cause current presentation of the subject makes it appear 

 tliat Ehrenberg was theoretically all wrong while Dujardin 

 was theoretically all right. 



Ehrenberg went astray not in defending the theory that 

 Infusion^thierchen possess organs, but in claiming for them 

 particular kinds of organs which they do not possess. Con- 

 vinced as he was, largely on a priori grounds, that the}' must 

 be organized, and knowing no other kind of organization 

 than tliat of the larger animals with which he was familiar, 

 he brought to his microscopic researches a mind prepared 

 to make the most possible of the general resemblance many 

 of the little creatures he studied bear to ordinary animals. 

 From pole to pole and in all depths of the ocean, he said, 

 live minute animal forms which resemble higher animals 

 ''wie Ahdrilcke einer Schablone'' — like the impress of a mould. 

 And that the little creatures are genuine organisms seemed 

 to Ehrenberg to be supported by tlie fact that the myriads 

 of them fall into species, genera, families, and so on, as do 



