ILLUSTKATIONS 



PLATES 



PLATE TO PACE PAGE 



I. Fossil and recent blue-green Algae (after Walcott) . . 18 



II. The Myelins : doubly refracting fatty globules from the adrenal 



cortex and liver 168 



III. The Myelins : Myelin forms from soap ; Ductile Crystals 



(after Lehmann) 176 



IV. The Myelins : Distortion of fluid crystals and aberrant forms 



of myelin globules 186 



V. Schema of the stages of fertilization of the ovum (after 



Boveri) 192 



VI. Schema of tissue relationships 312 



VII. Diagram of a lepidic and a hylic tissue .... 316 



FIGURES IN THE TEXT 



no. PAOE 



1. Diagram of chemical constitution of an amino-acid nucleus of 



a protein 75 



2. Diagram of constitution of a protein ring . . . .76 



3. Diagram of the affinities of a compound of two carbon atoms 



(after Bayliss) 77 



4. Diagram of cell to show nuclear skein with chromomeres . . 78 



5. Diagram of mode of growth and deduplication of the biophoric 



molecule . . . . . . . . .81 



6. Diagrammatic representation of the nature of enzyme action . 86 



7. Diagram of simple dissociation of peptone molecule . . 87 



8. Diagram of interaction of substratum and receptor through inter- 



mediation of enzyme . . . . . . .87 



