TABLE OF CONTENTS 



STATEMENT OF THE WORKING HYPOTHESIS 



CHAPTER I'Al.K 



INTRODUCTION, - ' 



I. THK SCOPE AND LIMITATIONS OF COMPARATIVE MORPHOLOGY, - 5 



II. THE LIFE-HISTORY OF A FERN, 14 



III. ON THE BALANCE OF THE ALTERNATING GENERATIONS OF 



ARCHEGONIATAE, 33 



IV. CYTOLOGICAL DISTINCTION OF THE ALTERNATING GENERATIONS 



OF ARCHEGONIATAE, - 4 6 



V. ALTERNATION IN THALLOPHYTES, 63 



VI. BIOLOGICAL ASPECT OF ALTERNATION, 79 

 VII. STERILISATION, - 



VIII. THF. SPORANGIUM DEFINED, 103 



IX. SOME GENERAL ASPECTS OF THE POLYSPORANGIATE STATE, 113 



X. VARIATIONS IN NUMBER OF SPORANGIA, 119 



XI. THEORY OF THE STROBILUS, 132 



XII. SPORANGIOPHORES AND SPOROPHYLLS, 144 



XIII. ON THE RELATIONS BETWEEN THE STERILE AND FERTILE REGIONS 



IN THE SPOROPHYTE, 156 



XIV. EMBRYOLOGY AND THE THEORY OF RECAPITULATION,- 173 

 XV. ANATOMICAL EVIDENCE, - 188 



XVI. SYMMETRY OF THE SPOROPHYTE, 201 



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