CONTENTS 
INTRODUCTION a) 9g) oswia ened 2G Sangh eo este lua avy ee 5 
CHAPTER I. 
Ontogeny, as a Recapitulation of Phylogeny suggests the Idea 
of a continuous Action exerted by the Germ Substance 
upon the Soma throughout the whole of Development.... 11 
CHAPTER II. 
1. Phenomena which indicate a continuous formative Action 
which is exerted by Parts of the Soma upon the other 
Parts throughout the Whole of Development ............ 19 
2. Hypothesis of the Nature of the formative Stimulus........ 29 
CHAPTER III. 
1. Phenomena which point to the Existence of a central Zone 
Of Development assese nace ssceeedanenso44 Sameree eeesen4as 53 
2. Hypothesis of the Structure of the germinal Substance..... 76 
CHAPTER IV. 
1. Phenomena which refute simple Epigenesis ............... 104 
2. Phenomena which refute Preformation ................... 121 
3. Inadmissibility of a homogeneous germ Substance.......... 144 
4. Inadmissibility of preformistic Germs..................065 150 
CHAPTER V. 
The Question of the Inheritance of acquired Characters ....... 159 
CHAPTER VI. 
The most important of the existing biogenetic Theories in Rela- 
tion to the Inheritance of acquired Characters ........... 224 
CHAPTER VII. 
The centroepigenetic Hypothesis and the Explanation of In- 
heritance afforded by it ........ce cet eec cree cere ences 289 
CHAPTER VIII. 
The Phenomenon of Memory and the vital Phenomenon....... 316 
COHGLUSION s.iicade-v'os 4 Saeieles veeee Ta Cte nt cna TE Se 356 
Appendix 2... cece eee eect cere nee ene renee ttn e nner neees aan ee 359 
[index .ccccccce ccc c cece teen e eres ees eeneeeee sees sereenneeeees 401 
