x TABLE OF CONTENTS 



PAGE 



B. Fixed colonies 29 



Apiocystis 29 



Diatomaceae 29 



Licmophora 30 



Hydrurus .......... 30 



II. Cell-dominions with vegetative points 33~4 



Regular laying down of lateral organs 34 



Long shoots and short shoots in different cycles of affinity . 35 



Sphacelarieae 36 



Florideae .......... 38 



IV. NORMAL FORMATION OF ORGANS AT THE VEGETATIVE POINT AND 



REGENERATION 41-51 



Normal sequence of formation of organs ...... 41 



Regeneration, its meaning 42 



I. Regeneration of the vegetative point 43~44 



In roots ........... 43 



In prothalli of ferns 43 



II. New formation of organs in regeneration 44~5i 



Replacement of lost parts 44 



Polarity in new formations 44 



Sachs' hypothesis of ' material and form ' 45 

 Influence upon severed parts of their previous organic 



relationships 45 



In Spermaphyta ......... 45 



In Pteridophyta . . 46 



In Bryophyta . 47 



In Fungi .......... 49 



V. CONCRESCENCE AND ARREST 51-61 



Introduction 51 



Value of these in comparative organography .... 51 



A. Concrescence 52-55 



Developmental .......... 52 



Congenital ........... 53 



Spathiphyllum .......... 55 



B. Arrest 56-61 



1. Kinds and manner 56 



Abortion ........... 56 



Suppression 56 



2. Causes of arrest 58 



<7. Through correlation 58 



b. Through loss of function ....... 58 



3. Morphological importance of arrested organs .... 60 



