DESIGN LV THE ORGAXIC WORLD. 



45 



FIG. V. 

 Diagram illustrating the Pedigree of the Complex type of Orbitolite, 



\. Simple undivided Spire of Cornuspira. 



2. I aiii.illy interrupted Spire of Spirohfulina. 



3. Spire of /V//&amp;lt;r&amp;lt;y&amp;gt;//&amp;gt;, divided by partitions into chambers. 



4. Spire of Or/&amp;gt;iinlina, its chambers divided into rows of chamberlets. 



5. I&amp;gt;i-&amp;gt;k of &quot;simple&quot; Orbitolite^ showing first-formed spire, surrounded by 

 concentric rings. 



6. I)i*k of &quot;duplex&quot; Orbitolite, showing earlier passage from spiral to 

 cyclical plan of growth. 



7. (Ji-ntial portion of Disk of &quot;complex&quot; Orbitolite, in which the cham 

 bered nucleus alone shows an abbreviated spire, the very first row of chamber- 

 lets forming a complete ring. 



