ORIGIN AND SIGNIFICANCE OF SEX. Ill 



of the magnet again holds good. The two masses 

 blend in their union the effects of their past experi- 

 ences as individual organisms. From the union 

 of the two organisms there may arise one or many 

 organisms, each displaying the results of the 

 influence of environment upon the two parent 

 organisms. This is the process of conjugation 

 which prevails largely among unicellular organisms. 

 If we may judge from the phenomena of heredity 

 in higher organisms, we conclude that each parent 

 organism transmits the effects of its already induced 

 changes to the progeny, thus producing new and 

 generally intermediate forms. We know, from the 

 observation of the higher animals, that the poten- 

 tialities of development of both parents are present 

 in the initial stages of the embryo, and that the 

 development proceeds this way or that way, accord- 

 ing to the stimuli brought to bear upon the embryo. 

 Thus the young of frogs have the power of develop- 

 ing like the mother or the father, and, as shown by 

 Professor Yung, their manner of development is de- 

 pendent upon the quantity and quality of their food. 

 The honey-bees furnish another illustration, for 

 among them the food and treatment which the 

 embryo receives, determines whether it shall grow 

 into a queen or a worker. Also there have been 

 described a large number of cases showing that 



