x Contents 



i r. \PTER PAGE 



heritance -material. (!6. Function of chromosomes in heredity 

 aryuin-d and nc<-<>ii<l<iry, 67. The two-fold character of the 

 j>n>b!i'in of hereditary substance, 70. The probability that 

 inheritance material becomes such in each ontogeny, 73. 

 Germ-cells subject to metabolism like all other cells, 74. 

 Chemical changes in germ-cells during parent's ontogeny, 75. 

 The possibility of changing sex by influences on the germ, 

 76. The determiner conception contrary to ordinary chem- 

 ical principles, 79. Endorsement of E. B. Wilson's proposal 

 to drop "determiner" from the vocabulary of genetics, 8%. 

 Advantages in conceiving germ-cell chromosomes as initia- 

 tors in hereditary development, S3. Inconclusiveness of the 

 cytological evidence usually appealed to in support of the 

 chromosome theory, 84. Summing up of the findings 

 against the chromosome theory, 87. Brief reference to the 

 untoward implications of the germplasm conception of 

 heredity, 89. 



PART II. THE CONSTRUCTIVE SIDE OF THE 

 ORGANISMAL CONCEPTION 



XVII. GROWTH INTEGRATION 93 



The field to be covered by the constructive discussion, 93. 

 Four types of bio-integration to be treated, 94- Graded 

 repetitive series as integrative phenomena, 95. Illustrations 

 from animals, 95. Illustrations from plants, 99. Justifica- 

 tion for bringing all these phenomena under one head, 103. 

 Attempted casual explanation of these series, 104- Axial 

 metabolic gradients as integrative phenomena,, 107. Meristic 

 gradients and metabolic gradients both phenomena of growth 

 integration, 111. 



XVIII. CHEMICO-FUNCTIONAL INTEGRATION 113 



Functional as contrasted with growth integration, 113. The 

 conception of "internal secretions," 114- Effects of removing 



the human thyroid for curative purposes, 115. Experimental 

 thyroid excision in normal lower animals, 117. The internal 

 secretion of the duodenal mucous membrane, 119. The na- 

 ture of the active substances in internal secretions, 121. The 

 close resemblances and interrelations of the different in- 

 ternal secretions, 124- Relation between the internal secre- 



