TRANSITIONS IN MORPHOLOGICAL CHARACTERS 127 



CONCLUSIONS 



1. The saccate type of Asplanchna amphora reproduces its 

 own type indefinitely when reared under uniform conditions. 



2. A marked physiological rhythm is present in the successive 

 development of generations. 



3. In the young successively produced by one individual 

 under uniform conditions, the mid-members of the family re- 

 ceive more nutrition from the mother that do the earlier or 

 later members. 



4. The size of the parent in lines with common ancestry and 

 without mutation does not directly influence the size of the 

 offspring. 



5. Change in temperature, in itself, has no direct influence in 

 producing morphological change. 



6. Starvation of the saccate type does not cause mutation. 



7. Starvation of the humped type causes retrograde muta- 

 tion. 



8. Alternate feeding and starvation in isolation cultures does 

 not cause -mutation. 



9. Alternate feeding and starvation in mass cultures probably 

 does cause mutation. 



10. Change of food, as from Paramecium to Oxytricha, P. 

 to Euglena, P. to Moina, P. to Brachionus, and P. to Hadatina 

 produces mutation. 



11. Substances dissolved in culture medium or in the water of 

 the food culture do not have a direct influence toward producing 

 a mutation. 



12. Production of males is rare in the saccate and abundant in 

 the humped and campanulate types. 



