210 VITALISM AND SCHOLASTICISM 



been lately attached to them, consideration 

 must now be given to this matter. In certain 

 instances such as that of the Aphides or green- 

 flies which are such a pest on roses, partheno- 

 genesis is the rule for a certain number of 

 generations at any rate, that is new individuals 

 arise without the previous union of male and 

 female elements. In other cases such an event 

 it would appear takes place sporadically, in- 

 deed it has been suggested that the occurence 

 of the curious teratomata in the ovary of the 

 human female and possibly, though doubtfully, 

 in the testis of the human male, may be at- 

 tempts at the same kind of thing in the highest 

 living form. 



Of late a good deal of attention has been 

 directed to the subject of artificial partheno- 

 genesis by the extremely interesting experi- 

 ments of Jacques Loeb.* He has succeeded 

 by methods physical and chemical in inducing 

 complete development in certain forms and, 

 most important of all, even in a vertebrate, 

 the frog, without previous impregnation. 



These experiments as to whose remarkable 

 character there can be no difference of opinion 

 are still in their infancy, and Sir William 

 Tilden one of the most distinguished of living 

 organic chemists has stated it as his opinion 



* The Organism as a Whole from a Physico-Chemical 

 Viewpoint. 



