igos.j JENNINGS— HEREDITY IN PROTOZOA. 545 



Page 

 4. Effects of Growth on the Observed Correlation between Length 



and Breadth 455 



IV. The Effects of Environmental Conditions on Dimensions, 



Variation and Correlation 45^ 



1. Progeny of D (caitdafiiin form) 459 



First Series 459 



Old Large Culture,- p. 459; Effects of Fresh Hay Infusion, 

 p. 459; Scarcity of Food, p. 462; Rapid Multiplication, p. 

 463; Injurious Bacteria, p. 464; Starvation, p. 464. 



Second Series 4^5 



Fresh Hay Infusion, p. 465 ; Starvation, p. 465 ; Effects of 

 Abundant Food on a Starving Culture, p. 465; Fluid 

 Unchanged for a Week, p. 469; Forty-eight Hours in 

 New Culture Fluid, p. 469; Resume, p. 469. 



Third Series 47^ 



2. Progeny of c (aurclia form) 473 



Random Sample, p. 473; Effect of Adding Boiled Hay, p. 473; 

 Effect of Fresh Hay Infusion, p. 473; Conjugating Culture, 

 p. 475 ; Scarcity of Food, after Conjugation, p. 475; Variation 

 in Different Divisions of the Same Pure Line, on the Same 

 Date, p. 475 ; Effects of Lack of Food, p. 476. 



3. Summary on the Effects of the Environment 47^ 



Effect on Length, p. 476; Effect on Breadth, p. 477; Relation of 

 Length to Nutrition, p. 477; Relation of Breadth to Nu- 

 trition, p. 477; Proportion of Breadth to Length, p. 478; 

 Effect of Environment on Variation, p. 479; Effect of En- 

 vironment on Correlation, p. 481. 

 V. Inheritanxe of Size 484 



1. Selection for Different Races in a Wild Culture 4^5 



a. Races Isolated from Cultures Not Conjugating — Procedure 



Necessary for Making the Conditions Identical for Dif- 

 ferent Lines 485 



b. Are the Lines of Different Size Merely Different Stages in 



the Life Cycle ? 492 



c. Other Evidences of Permanent Differentiation in Size, Inde- 



pendent of the Life Cycle 497 



d. Lines Intermediate between the two Main Groups. The 



Question of Species in Paramecium 498 



e. Do the Diverse Lines Differ in Other Respects besides 



Dimensions ? 500 



2. Results of Selection within Pure Lines 503 



a. Differences Due to Environmental Action Not Inherited. . . . 504 

 . b. Selection from among Dift'ering Individuals in the Same 



Environhient 505 



c. Summary on Selection within Pure Lines 511 



