TABLE 3.--Reciprocal Values Used to Determine Distances Between Elements of the Model; Each Value Represents the Average of Serological Tests Between the Species Involved Table Headings: Col A: _Estrilda amandava_ Col B: _Poephila guttata_ Col C: _Richmondena cardinalis_ Col D: _Spiza americana_ Col E: _Spinus tristis_ Col F: _Junco hyemalis_ Col G: _Zonotrichia querula_ ==========================+====+====+====+====+====+====+====+ | A | B | C | D | E | F | G | --------------------------+----+----+----+----+----+----+----+ _Estrilda amandava_ | .. | 92 | .. | 72 | 72 | 59 | .. | --------------------------+----+----+----+----+----+----+----+ _Poephila guttata_ | 92 | .. | 74 | 78 | 78 | .. | .. | --------------------------+----+----+----+----+----+----+----+ _Richmondena cardinalis_ | .. | 74 | .. | 85 | 63 | 77 | 79 | --------------------------+----+----+----+----+----+----+----+ _Spiza americana_ | 72 | 78 | 85 | .. | 77 | 77 | 85 | --------------------------+----+----+----+----+----+----+----+ _Spinus tristis_ | 72 | 78 | 63 | 77 | .. | .. | .. | --------------------------+----+----+----+----+----+----+----+ _Junco hyemalis_ | .. | .. | 77 | 77 | .. | .. | .. | --------------------------+----+----+----+----+----+----+----+ _Zonotrichia querula_ | .. | .. | 79 | 85 | .. | .. | .. | --------------------------+----+----+----+----+----+----+----+ TABLE 4.--Single Values Used to Determine Distances Between Elements of the Model; Each Value Represents a Single Test Between the Species Involved Table headings: Col A: _Estrilda amandava_ Col B: _Poephila guttata_ Col C: _Piranga rubra_ Col D: _Richmondena cardinalis_ Col E: _Spinus tristis_ Col F: _Junco hyemalis_ Col G: _Zonotrichia querula_ ==========================+====+====+====+====+====+====+====+ | A | B | C | D | E | F | G | --------------------------+----+----+----+----+----+----+----+ _Passer domesticus_ | .. | 74 | 73 | .. | 72 | .. | .. | --------------------------+----+----+----+----+----+----+----+ _Molothrus ater_ | .. | 54 | .. | 65 | .. | 69 | 75 | --------------------------+----+----+----+----+----+----+----+ _Piranga rubra_ | .. | 77 | .. | 91 | 73 | 74 | .. | --------------------------+----+----+----+----+----+----+----+ _Carpodacus purpureus_ | 70 | 71 | .. | 61 | 93 | .. | .. | --------------------------+----+----+----+----+----+----+----+ [Illustration: FIGS. 10-13. Graphs of precipitin reactions illustrating effects of formalin on antigenicity and reactivity of the extracts. For further information, see text, pp. 190-193.