170 GENERAL BIOLOGY 



rapid series of divisions, producing a cell-mass which 

 roughly resembled a larva. This was, however, 

 without cellular organization, and eventually went 

 to pieces. Such cell development at random is 

 suggestive of the condition we find in tumors and 

 galls, reproduction without organization. 1 In the 

 case of Chcetopterus, however, differentiation may 

 take place even without cellular organization. 



It was found that the eggs of other animals, 2 when 

 ripe, can be induced to segment by a variety of 

 means, shaking, varying the osmotic pressure 

 of the sea- water, acids, CO 2 , etc., all being effective, 

 though not always for the same species. 



Continuing these experiments, a number of Ameri- 

 can investigators, among whom Professor Jacques 

 Loeb is the most conspicuous, have succeeded in 

 imitating, artificially, the processes of Nature, by 

 inducing unfertilized eggs to develop normally by 

 chemical and physical means. The methods em- 

 ployed have been complicated, and the data are as 

 yet too incomplete to afford a basis for generalization, 

 but such experiments show that probably all eggs 

 contain within themselves all the potentialities for 

 normal development, and that " fertilization " or 

 zygosis is only an accompaniment to, not a necessity 

 for, individual development. 3 



1 Mature eggs that are not fertilized quickly disintegrate (autolysis). 

 The potassium prolonged the life of the protoplasm hi theabove experiment. 



2 The sea-urchin is a favorite form for experiment. 



3 In spite of the truth of this statement we must not lose sight of the 

 profound significance of the phenomenon of zygosis from another stand- 

 point. The mixture of germinal substance (amphimixis) that results 



