Figs. 18-21. Graphs of precipitin reactions illustrating serological relationships. For further explanation, see text, pp.[ 190-193].
Fig. 18. Serological relationships of Spinus and Poephila with the richmondenines. Fig. 19. Serological relationships of Carpodacus and Spinus with Richmondena and Piranga. Fig. 20. Serological relationships of Poephila and Richmondena with the carduelines. Fig. 21. Serological relationships of Richmondena and Spinus with the estrildines.
Fig. 22. Two views of a model illustrating serological relationships among fringillid and related birds. For further explanation, see text, pp.[ 193-194].
| Genera | Pi | . . . . | Piranga | |||
| C | . . . . | Carpodacus | Po | . . . . | Poephila | |
| E | . . . . | Estrilda | R | . . . . | Richmondena | |
| J | . . . . | Junco | Sn | . . . . | Spinus | |
| M | . . . . | Molothrus | Sz | . . . . | Spiza | |
| Pa | . . . . | Passer | Z | . . . . | Zonotrichia | |