Part 4

The upper group offspring of Table 55, second division, the homozygous and heterozygous mutants, number 68; they have a mean grade of 4.77 as compared with 4.43 in F₁, which consisted exclusively of heterozygotes. This shows the extracted homozygotes to be of higher grade than the heterozygotes. The highest grade mutant among the 31 F₁ young, all of which were heterozygotes, was of grade 5, but among the 68 F₂ young are 16 of higher grade than 5. We expect one-third of these 68 individuals to be homozygotes. Now all of the F₂ mutants from the cross of mutant with plus race (Table 54) were of grade 5 or higher, only 2 in 79 being as low as 5, and 13 of the 79 being of grade 5¾, a grade not attained at all in F₂ from the mutant-minus cross (Table 55). This result shows us that the cross with the minus race does affect permanently the mutant character, lowering its grade even in homozygous mutants extracted from the cross. It also increases the variability of the mutants, for the standard deviation of the mutant group in Table 55 is 0.44, whereas in Table 54 (mutant-plus F₂), in a like number of individuals, it was 0.15, or only about one-third as great.

That the variability of the mutants is unaffected by a cross with the plus race, but that it is increased by a cross with the minus race, and that, further, the mean of the mutants is affected little or none by a cross with the plus race, but that it is lowered by a cross with the minus race—these several facts are all conformable with the hypothesis that _the change in variability due either to crossing or to selection results from modifying factors_ which, as they are independent of the main factor concerned, are probably transmitted in a different part or component of the germ-cell than that factor. For if the mutant and the plus race are alike as regards the modifiers, but differ only in the main factor, then no change in variability should result from intercrossing them, but only alternative conditions as regards the main factor. This is the observed result. But if the mutant and the minus race differ not only in the main factor, but also in modifiers which are independent of it, then, when they are crossed, we may expect that through independent segregation of main factor and modifiers the extracted minus race will be raised in grade, while the extracted mutants are lowered, and both will become more variable. This also is the observed result.

One objection may be offered to this interpretation, namely, that the increased variability is not delayed until F₂, but is already in evidence to some extent in F₁. The same thing was observable in the crosses of the plus and minus series (Table 50). From that table, Series 1, it will be observed that when the plus and minus races had standard deviations of 0.49 and 0.50, respectively, their F₁ offspring had a standard deviation of 0.71, an increase by nearly one-half; F₂ showed a further increase to 1.01. In series 2, Table 50, the uncrossed races (generation 10) had standard deviations of 0.36 and 0.24; their F₁ offspring had a standard deviation of practically twice this, namely 0.60; F₂ showed a further increase to 0.87.

At the time of the mutant-minus race crosses, the minus race (generation 10) had a standard deviation of 0.24, the plus race of 0.36. F₁ (lower group) had a standard deviation of 0.77, and F₂ of 1.17. F₁ mutants (upper group) had a standard deviation of 0.31 which rose in F₂ to 0.44. These various facts will perhaps be better grasped if presented in tabular form:

TABLE C.

+-------------------------------------+-------------------+------+------+ | |Standard deviation | | | | | of races crossed, | S. D.| S. D.| | | same generation. | F₁ | F₂ | +-------------------------------------+---------+---------+------+------+ |Plus-minus cross, series 1 (Table 50)| 0.49 | 0.50 | 0.71 | 1.01 | |Plus-minus cross, series 2 (Table 50)| .36 | .24 | .60 | .87 | |Mutant-minus cross, lower group | .25 | .24 | .77 | 1.17 | |Mutant-minus cross, upper group | .19 | .24 | .31 | .44 | |Mutant-plus cross, lower group | .25 | .36 | .24 | .35 | |Mutant-plus cross, upper group | .19 | .36 | .23 | .15 | +-------------------------------------+---------+---------+------+------+

The mutant-plus cross, it will be observed, shows no increase of variability either in F₁ or in F₂, but crosses involving the minus race show increase of variability both in F₁ and in F₂. Interpreted on a Mendelian basis, this means that the mutant and plus races on the one hand and the minus race on the other hand differ by more than a single factor. If they differed by only a single factor, then crosses between them should bring no increase of variability, either in F₁ or in F₂. This appears to be true as regards the mutant and plus races when crossed with each other. But if the races crossed differ by more than one factor, and if, further, neither parent is homozygous as regards the factors in which they differ, then we may expect an increase in variability both in F₁ and in F₂. This is exactly what we observe when the minus race is crossed with either the plus race or its derivative, the mutant race.

If we suppose that the plus race and the minus race differ from each other by certain “modifiers,” we can not suppose that the plus and the mutant races differ by these same modifiers. They differ in some other _single_ respect; perhaps that in which they differ is the _main_ hooded factor. Are we, then, to suppose that the plus and the minus races _do not_ differ as regards this same main factor? This can not be stated, but we see no reason for considering them identical as regards that factor. It appears that the mutant race arose from the plus race by a single large plus variation, which seems to have its determiner in some single component of the germ-cell. But the fact that this change came as a large quantitative variation does not show that small variations are impossible in that same cell component. It seems to us quite improbable that the plus mutation could have arisen in the minus selection series. We believe that the repeated selection which was practised had something to do with inducing this change in the plus direction. If one can increase at will the “modifiers” which make the pigmentation more extensive, it does not seem strange that after a time a readjustment should occur within the cell which should incorporate modifiers in that part of the cell which is responsible for the unit-character behavior of the hooded pattern. This would amount to a quantitative change in the unit-character for hooded pigmentation.

BIBLIOGRAPHY.

CASTLE, W. E.

1905. Heredity of coat characters in guinea-pigs and rabbits. Carn. Inst. Wash. Pub. 23.

1906. The origin of a polydactylous race of guinea-pigs. Carn. Inst. Wash. Pub. 49.

1912. The inconstancy of unit-characters. American Naturalist, vol. 46, pp. 352-362.

CASTLE, W. E., and ALEXANDER FORBES.

1906. Heredity of hair-length in guinea-pigs and its bearing on the theory of pure gametes. Carn. Inst. Wash. Pub. 49.

DE VRIES, H.

1901-1903. Die Mutationstheorie. Veit & Co., Leipzig.

EAST, E. M.

1912. The mendelian notation as a description of physiological facts. American Naturalist, vol. 46, pp. 633-655.

JENNINGS, H. S.

1909. Heredity and variation in the simplest organisms. American Naturalist, vol. 43, pp. 321-337.

1910. Experimental evidence on the effectiveness of selection. American Naturalist, vol. 44, pp. 136-145.

JOHANNSEN, W.

1909. Elemente der exakten Erblichkeitslehre. G. Fischer, Jena.

MACCURDY, H., and W. E. CASTLE.

1907. Selection and cross-breeding in relation to the inheritance of coat-pigments and coat-patterns in rats and guinea-pigs. Carn. Inst. Wash. Pub. 70.

PEARL, R.

1913. Genetics and breeding. Science, n. s., vol. 37, pp. 539-546.

TABLES.

TABLE 1.—_Classification of the first generation of offspring in the plus selection series. At the head of each column is indicated the grade of the individuals recorded in that column. The figures in the body of the table indicate the numbers of offspring of the several grades indicated._

+--------+--------------------------+-------+------+-----------+ | Grade | Grade of offspring. | | | | | of +--+--+--+--+--+--+--+--+--+Totals.|Means.|Regression.| |parents.|+1|1¼|1½|1¾| 2|2¼|2½|2¾| 3| | | | +--------+--+--+--+--+--+--+--+--+--+-------+------+-----------+ | 1⅞ | 1| 1| 1| 1| 1| | 1| 1| | 7 | 1.82 | .05 | | 2 | 4| 1| 3| 1| 4| 1| 4| | | 18 | 1.76 | .24 | | 2⅛ | | | | | | | | | | | | | | 2¼ | 3| 1| 3| 1| 6| 2| 2| 2| | 20 | 1.87 | .38 | | 2⅜ | | | | | | | | | | | | | | 2½ | 5| | 3| 1|13| 1| 8| 5| 1| 37 | 2.06 | .44 | | 2⅝ | | | | | | 1| 1| 2| 1| 5 | 2.15 | .47 | | 2¾ | 7| | 3| 2|17| 1|12| | 9| 51 | 2.12 | .63 | | 2⅞ | | | | | | | | | | | | | | 3 | | | | 2| 3| 1| 3| | 3| 12 | 2.35 | .65 | | +--+--+--+--+--+--+--+--+--+-------+------+-----------+ |Totals | | | | | | | | | | | | | | or | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | 2.51|20| 3|13| 8|44| 7|31|10| 4| 150 | 2.05 | .46 | +--------+--+--+--+--+--+--+--+--+--+-------+------+-----------+

TABLE 2.—_Classification of offspring in generation 2, plus selection series._

+--------+-----------------------------------------------------------+ | Grade | Grade of offspring. | | of +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |parents.|-1|-¾|-½|-¼| 0|+¼| ½| ¾| 1|1¼|1½|1¾| 2|2¼|2½|2¾| 3|3¼|3½|3¾| +--------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | 2 | | | 1| | 1| | | 4| 2| 5| 7| 3| 7| 8| 2| 3| 2| 1| | | | 2⅛ | 1| | 1| | 2| 1| 3| 5|12| 8| 5| 5| 8| 2| 1| 2| | | | | | 2¼ | | | | | | | | | | 1| 1| 3| 1| 1| | 1| | | | | | 2⅜ | | | | | | | | | 1| 1| 4| 9| 7| 8| 8| 6| 1| | | | | 2½ | | | | | | | | 4|22|16|19|11|21|13| 7|10| 9| 1| | | | 2⅝ | | | | | 1| | 2| | 3| 1| | 6| 5| 7| 9| 6| 3| 1| | | | 2¾ | | | | 1| | | | 3| 4| 2| 6| 5| 9| 6| 9| 6| 1| | | | | 2⅞ | | | | | | | | | | 1| | 1| 3| 5| 3| 9| 1| | | | | 3 | | | | | | | | | 1| 2| 3| 2|14| 7| 4| 5|11| 6| 3| 1| | 3½ | | | | | | | | | | | | | 2| | 1| | 2| | | | | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |Totals | | | | | | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | | | | | | 2.52| 1| -| 2| 1| 4| 1| 5|16|45|37|45|45|77|57|44|48|30| 9| 3| 1| +--------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

+--------+-------+------+-----------+ | Grade | | | | | of |Totals.|Means.|Regression.| |parents.| | | | +--------+-------+------+-----------+ | 2 | 46 | 1.70 | .30 | | 2⅛ | 56 | 1.28 | .82 | | 2¼ | 8 | 1.87 | .38 | | 2⅜ | 45 | 1.92 | .45 | | 2½ | 133 | 1.80 | .70 | | 2⅝ | 44 | 2.11 | .51 | | 2¾ | 52 | 1.92 | .83 | | 2⅞ | 23 | 2.41 | .46 | | 3 | 59 | 2.47 | .53 | | 3½ | 5 | 2.50 | .62 | | +-------+------+-----------+ |Totals | | | | | or | | | | |means, | | | | | 2.52| 471 | 1.92 | .60 | +--------+-------+------+-----------+

TABLE 3.—_Classification of offspring in generation 3, plus selection series._

+--------+-----------------------------------------+---------------------+ | Grade | Grade of offspring. |Totals. | | of +--+--+--+--+--+--+--+--+--+--+--+--+--+--+ Means. | |parents.| ¾| 1|1¼|1½|1¾| 2|2¼|2½|2¾| 3|3¼|3½|3¾| 4| Regression.| +--------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+------+--------+ | 2⅛ | | | 1| 1| 5| 6| 4| 1| 3| | | | | | 21 | 2.06 | .06 | | 2¼ | | | | | | | | | | | | | | | | | | | 2⅜ | | | | | 5| 5| 1| 4| 2| | | | | | 17 | 2.15 | .22 | | 2½ | 1| 2| 1| 2| 5| 5|10|10| 9| 7| 2| | | | 54 | 2.32 | .18 | | 2⅝ | | | 2| 1| 3| 9| 4| 5|15|18| 3| 1| 2| 1| 64 | 2.64 | -.02 | | 2¾ | | | | 2| 1| 7|10| 7| 7| 7| 1| 1| | | 43 | 2.46 | .29 | | 2⅞ | | | 1| | | 7| 3| 7| 9|10| 9| 1| | | 47 | 2.70 | .17 | | 3 | | | | 2| 1|12|14|11|17|11| 3| | | | 71 | 2.49 | .51 | | 3⅛ | | | | | | | | | 2| 5| 1| 2| | | 10 | 3.07 | .05 | | 3¼ | | | | | | | | | 1| 2| | 1| 2| | 6 | 3.17 | .08 | | 3⅜ | | | | | | | | 2| 1| 3| 2| | | | 8 | 2.91 | .46 | | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+------+--------+ |Totals | | | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | | | 2.73| 1| 2| 5| 8|20|51|46|47|66|63|21| 6| 4| 1| 341 | 2.51 | .22 | +--------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+------+--------+

TABLE 4.—_Classification of offspring, generation 4, plus selection series._

+--------+---------------------------------------+-----------------------+ | Grade | Grade of offspring. |Totals. | | of +--+--+--+--+--+--+--+--+--+---+--+--+--+ Means. | |parents.| ¾| 1|1¼|1½|1¾| 2|2¼|2½|2¾| 3 |3¼|3½|3¾| Regression.| +--------+--+--+--+--+--+--+--+--+--+---+--+--+--+-----+------+----------+ | 2½ | | | | | 2| | 2| | 4| 3| | | | 11 | 2.55 | .05 | | 2⅝ | | | | | | | | | | | | | | | | | | 2¾ | | | | | | 3| 3| 2| 3| 4| 3| | | 18 | 2.65 | .10 | | 2⅞ | | 1| | | | | 3| 3| 7| 15| 4| 3| 2| 37 | 2.97 | .10 | | 3 | | 1| | 1| 7|12|25|19|35| 29| 9| 4| 1| 143 | 2.60 | .40 | | 3⅛ | | | 1| | 2|11|14|21|28| 30|11| 2| 2| 122 | 2.69 | .43 | | 3¼ | | | | 1| | 1| 6| 8|13| 17| 9| 8| 1| 64 | 2.89 | .36 | | 3⅜ | | | | | 1| | 6| 2| 3| 9| 2| | | 23 | 2.70 | .67 | | 3½ | | | | | | 3| 1| | 2| 3| 6| 2| 3| 20 | 3.02 | .48 | | 3⅝ | | | | | | | | | | | | | | | | | | 3¾ | | | | | | | | 3| 1| 1| 1| | | 6 | 2.75 | 1.00 | | +--+--+--+--+--+--+--+--+--+---+--+--+--+-----+------+----------+ |Totals | | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | | 3.09| 1| 1| 1| 2|12|30|60|58|96|110|45|19| 9| 444 | 2.73 | .36 | +--------+--+--+--+--+--+--+--+--+--+---+--+--+--+-----+------+----------+

TABLE 5.—_Classification of generation 5, plus selection series._

+--------+-----------------------------------------------+ | Grade | Grade of offspring. | | of +--+--+--+--+--+--+--+--+---+---+---+--+--+--+--+ |parents.| ¾| 1|1¼|1½|1¾| 2|2¼|2½| 2¾| 3 | 3¼|3½|3¾| 4|4¼| +--------+--+--+--+--+--+--+--+--+---+---+---+--+--+--+--+ | 2¾ | | | | | | 1| | | 2| 4| 4| 1| | | | | 2⅞ | | | | | | | 4| 4| 4| 2| 3| 2| 2| | | | 3 | | | | | | | 1| 5| 3| 2| 3| 1| | | | | 3⅛ | | 1| 1| 1| 1| 8| 9|14| 20| 29| 18| 8| 3| 1| | | 3¼ | 1| 1| 1| | 4|12| 6|14| 24| 39| 27| 7| | 1| 1| | 3⅜ | | | | 1| 1| 5|14|11| 25| 36| 28|15| 7| 2| | | 3½ | | | | | | 6| 5|10| 14| 16| 8| 8| 3| | | | 3⅝ | | | | | | 3| 3| 5| 7| 16| 12|11| 4| 3| | | 3¾ | | | | | | | | 2| 2| 4| 3| 2| 1| | | | 3⅞ | | | | | | | 1| 1| | 1| | 1| 2| 2| | | 4 | | | | | | | 1| | | 1| 1| 1| 2| 1| | | 4⅛ | | | | | | 1| | | | 1| | | | 1| | | +--+--+--+--+--+--+--+--+---+---+---+--+--+--+--+ |Totals | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | 3.33| 1| 2| 2| 2| 6|35|44|66|101|151|107|57|24|11| 1| +--------+--+--+--+--+--+--+--+--+---+---+---+--+--+--+--+

+--------+-------+------+-----------+ | Grade | | | | | of |Totals.|Means.|Regression.| |parents.| | | | +--------+-------+------+-----------+ | 2¾ | 12 | 3.00 | -.25 | | 2⅞ | 21 | 2.87 | 0 | | 3 | 15 | 2.81 | .19 | | 3⅛ | 114 | 2.81 | .31 | | 3¼ | 138 | 2.81 | .44 | | 3⅜ | 145 | 2.94 | .43 | | 3½ | 69 | 2.86 | .64 | | 3⅝ | 64 | 3.08 | .54 | | 3¾ | 14 | 3.07 | .68 | | 3⅞ | 8 | 3.35 | .52 | | 4 | 7 | 3.36 | .64 | | 4⅛ | 3 | 3.00 | 1.12 | | +-------+------+-----------+ |Totals | | | | | or | | | | |means, | | | | | 3.33| 610 | 2.90 | .43 | +--------+-------+------+-----------+

TABLE 6.—_Classification of generation 6, plus selection series._

+--------+------------------------------------------+--------------------+ | Grade | Grade of offspring. |Totals. | | of +--+--+--+--+--+---+---+---+---+--+--+--+--+ Means. | |parents.|1½|1¾| 2|2¼|2½| 2¾| 3 | 3¼| 3½|3¾| 4|4¼|4½| Regression.| +--------+--+--+--+--+--+---+---+---+---+--+--+--+--+-----+------+-------+ | 3 | | | | | | 1| | | | 1| | | | 2 | | | | 3⅛ | | 3| 4| 1| 1| 4| 7| 5| 3| | | | | 28 | 2.84 | .28 | | 3¼ | 1| | 3| 3| 8| 26| 31| 31| 24|15| 1| | | 143 | 3.10 | .15 | | 3⅜ | 1| | 5| 6|13| 20| 28| 30| 14| 5| | | | 123 | 2.96 | .41 | | 3½ | | 1| 9| 4|15| 29| 49| 41| 43|17| 4| | | 212 | 3.10 | .40 | | 3⅝ | | | 4| 8|11| 24| 34| 36| 37|21| 5| | 1| 181 | 3.16 | .46 | | 3¾ | 1| 1| 2| 1| 3| 4| 18| 13| 20|13| 2| | | 78 | 3.22 | .53 | | 3⅞ | | | 4| 1| 3| 5| 14| 15| 20|14| 4| | | 80 | 3.26 | .61 | | 4 | | | 1| | | | 2| 1| 5| 4| 1| | | 14 | 3.41 | .59 | | +--+--+--+--+--+---+---+---+---+--+--+--+--+-----+------+-------+ |Totals | | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | | 3.52| 3| 5|32|24|54|113|183|172|166|90|17| | 1| 861 | 3.11 | .41 | +--------+--+--+--+--+--+---+---+---+---+--+--+--+--+-----+------+-------+

TABLE 7.—_Classification of generation 7, plus selection series._

+--------+----------------------------------------------+ | Grade | Grade of offspring. | | of +--+--+--+--+--+---+---+---+---+---+--+--+--+--+ |parents.|1½|1¾| 2|2¼|2½| 2¾| 3 | 3¼| 3½| 3¾| 4|4¼|4½|4¾| +--------+--+--+--+--+--+---+---+---+---+---+--+--+--+--+ | 3⅛ | | | 2| 2| 4| 5| 7| 4| 3| 1| | | | | | 3¼ | 1| | 6|11| 7| 11| 30| 19| 22| 23| 1| | | | | 3⅜ | 1| 2|10|18|17| 21| 27| 18| 21| 20| 4| 1| | | | 3½ | | | 6| 9| 9| 21| 31| 28| 35| 34| 3| 1| | | | 3⅝ | | | 7|11|13| 26| 47| 53| 75| 49| 7| 1| | | | 3¾ | | | 2| 3| 3| 16| 28| 25| 58| 42| 4| 3| | | | 3⅞ | | | 2| 1| 2| 4| 10| 12| 23| 21| 6| 6| 2| 1| | 4 | | | | | 1| 1| 3| | 2| 4| 3| | | 1| | 4⅛ | | | | | | | | | 1| 1| 1| | | | | +--+--+--+--+--+---+---+---+---+---+--+--+--+--+ |Totals | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | 3.56| 2| 2|35|55|56|105|183|159|240|195|29|12| 2| 2| +--------+--+--+--+--+--+---+---+---+---+---+--+--+--+--+

+--------+-------+------+-----------+ | Grade | | | | | of |Totals.|Means.|Regression.| |parents.| | | | +--------+-------+------+-----------+ | 3⅛ | 28 | 2.87 | .25 | | 3¼ | 131 | 3.09 | .16 | | 3⅜ | 160 | 2.97 | .40 | | 3½ | 177 | 3.18 | .32 | | 3⅝ | 289 | 3.23 | .39 | | 3¾ | 184 | 3.35 | .40 | | 3⅞ | 90 | 3.49 | .38 | | 4 | 15 | 3.53 | .47 | | 4⅛ | 3 | 3.75 | .50 | | +-------+------+-----------+ |Totals | | | | | or | | | | |means, | | | | | 3.56| 1077 | 3.20 | .36 | +--------+-------+------+-----------+

TABLE 8.—_Classification of generation 8, plus series._

+--------+---------------------------------------+-----------------------+ | Grade | Grade of offspring. |Totals. | | of +--+--+--+--+---+---+---+---+--+--+--+--+ Means. | |parents.|1¾| 2|2¼|2½| 2¾| 3 | 3¼| 3½|3¾| 4|4¼|4½| Regression.| +--------+--+--+--+--+---+---+---+---+--+--+--+--+------+------+---------+ | 3¼ | | | | | | 2| | 2| | | | | 4 | 3.25 | 0 | | 3⅜ | | | | | | | | | | | | | | | | | 3½ | | | | 1| 4| 6| 9| 18| 17| 2| 2| | 59 | 3.46 | .04 | | 3⅝ | 1| 2| 9|13|30| 69| 44|144|149|22| 1| | 484 | 3.50 | .12 | | 3¾ | | 2| 1| 9|12| 55| 39|152|173|23| 2| | 469 | 3.49 | .26 | | 3⅞ | | 1| 2| | 4| 23| 18| 98| 69|19| 2| 1| 238 | 3.53 | .34 | | 4 | | | 1| 2| 3| 10| 6| 34| 6| 1| 1| | 64 | 3.31 | .69 | | 4⅛ | | | | | 2| 5| 2| 14| 13|14|10| | 60 | 3.72 | .40 | | 4¼ | | | | | | | 1| 7| 11| 2| 1| | 22 | 3.69 | .56 | | 4⅜ | | | | | | | | | 2| 5| 1| | 8 | 3.96 | .41 | | +--+--+--+--+--+---+---+---+---+--+--+--+------+------+---------+ |Totals | | | | | | | | | | | | | | | | | or | | | | | | | | | | | | | | | | |means, | | | | | | | | | | | | | | | | | 3.75| 1| 5|13|25|55|170|119|469|440|88|20| 1| 1408 | 3.48 | .27 | +--------+--+--+--+--+--+---+---+---+---+--+--+--+------+------+---------+

TABLE 9.—_Classification of generation 9, plus series._