Part 13
Family 4 (Pedigree Chart, No. K 6) illustrates the same kind of facts and conclusions. In the A Generation a Frenchman, whose eye-colour was unknown to my informant, married a full blood Indian princess who had Indian brown eyes. There was one daughter only (Generation B) by this marriage, and she had Indian brown eyes. She married an Irishman, who had red hair, grey eyes, and a freckled complexion (Generation B). From this marriage there came six children (Generation C). Two of these had "grey eyes like their father." Three had dark brown eyes of European tint. My informant had some doubt as to the European tint of two of these three (Nos. 3 and 4, C Generation); their eye-colour was very dark brown, and possibly it may have been the Indian tint. The remaining member of this generation had Indian brown eyes of a very dark shade.
It may be desirable to state that Families 4 and 5 come from different parts of Canada.
The chief feature of interest in this family is the segregation of the grey eye-colour of the Irishman among his offspring. It appears in two daughters. From what we know of analogous cases, there is little doubt that the gametes of his half-breed Indian wife carried the blue or grey factors derived from her French father. The appearance of an European brown eye-colour in Generation C, No. 6, suggests that the French grandfather had brown eyes, and that, therefore, this colour has segregated out among the gametes of the half-breed Indian mother.
Exhibited by Mr. E. Nettleship.
[Sidenote: L]
[Sidenote: L 1]
+Congenital Colour-blindness+. Pedigree showing unusual features, viz.: (_a_) females affected; (_b_) twins, of whom one is affected, the other not; (_c_) marriage between two unrelated colour-blind stocks. Except that two females are affected the inheritance, so far as can be traced, has followed the rule for colour-blindness; viz., limitation to males and transmission through unaffected females.
_Key to Signs_.
[M] normal male; [F] normal female. [M-] colour-blind male; [F-] colour-blind female. [circle] batch of whom there are no particulars. [OO with over bar] twins. [Greek: ph] died in infancy. [ob]: dead. [×] seen and examined. [× ×] reported normal, but not seen.
[Sidenote: L 2]
+Hereditary night-blindness with myopia+ (short sight) affecting 21 males and only 1 female in a large pedigree. The night-blindness congenital and stationary. Descent always through mothers themselves unaffected. Mental defects in several of the night-blind stock. Other pedigrees of this male-limited night-blindness are on record.
_Key_.
[M-] and [F-] night-blind male and female. Otherwise the same as for L 1.
[Sidenote: L 3]
Pedigrees of +hereditary congenital Nystagmus+ (involuntary rhythmical movements of the eyes) showing two different modes of descent.
[Sidenote: L 3a]
In Figure L 3a the nystagmus occurs only in males and descends through unaffected females.
[Sidenote: L 3b]
In Fig. L 3b both males and females are liable to the disease, and either parent may transmit it, although descent is more often through mother than father.
The movements of the eyes are very often accompanied by rhythmical movements of the head in the non-sex-limited type (Fig. L 3b), but head movements very seldom occur in the male-limited type (Fig. L 3a).
In both types many of those affected have also optical defects of the eyes, especially astigmatism. No mental or nerve complications in either kind.
_Key_.
[M-] and [F-] male and female with Nystagmus. Otherwise as for L 1.
[Sidenote: L 4]
Pedigree of +hereditary Cataract+. The cataract in this genealogy begins in childhood, and usually progresses so as to require operation by the time its subject is grown up; results of operation usually good and lasting. Most of the affected members still living; of the four dead, none died before 54, and two of them lived to 78 and 83 respectively. Both sexes affected and either sex may transmit. No other eye disease and no prevalent constitutional diseases or degeneracies in the cataractous stock.
Many similar pedigrees are known.
_Key_.
[M-] and [F-] male and female with cataract. Otherwise as for L 1.
[Sidenote: M]
Exhibited by Professor R. C. Punnett, F.R.S.
Mendelian Inheritance in Rabbits.
[Sidenote: M 1.]
Yellow Himalayan Dutch × (Black) | F_{1} Agouti (reversion to wild colour). | F | ______________________|__________________________ | | | | | Agouti Black Yellow Tortoise Himalayan +Ratio.+ 27 9 9 3 16
Factors concerned:--
+A+. the factor for agouti which turns a black into an agouti, or a tortoise into a yellow.
+E+. the factor for extension of pigment which when present turns a yellow into an agouti, or a tortoise into a black.
+S+. the factor for self colour which turns a Himalayan into a self coloured animal.
All the rabbits in this experiment contain the factor for black (B).
[Sidenote: M 2.]
The Himalayan pattern can occur in all four colour classes. Thus the agouti Himalayan has lighter points than the black Himalayan. (cf. 2 specimens shown.)
Experiments to demonstrate that +black rabbits may be of different constitution genetically+.
Factors concerned in these experiments are:--
+A+. the agouti factor.
+E+. the factor for extension of pigment.
+D+. a factor for density of pigmentation.
All the rabbits are homozygous for the black factor +B+.
Homozygous agouti = +AA BB EE+.
Black rabbits may be either:--
(1) Rabbits of the constitution +aa BB EE+. These breed true and behave as simple recessive to agouti.
(2) Rabbits of the constitution +AA BB EE DD+., _i.e._, agoutis to which a double dose of D has been added are pure blacks in appearance, when only a single dose of D is added the animal shows some agouti markings and is an agouti-black. Such rabbits have always proved to be heterozygous, and when mated together give blacks, agouti-blacks, and agoutis in the ratio 7:6:3.
(3) Rabbits of the constitution +AA BB Ee Dd+. An agouti-black (AA BB EE Dd) becomes a pure black when heterozygous for E. Such blacks when mated with blacks of constitution +aa BB EE dd+ throw some agoutis and also some agouti-blacks.
Further, the experiments have shewn that the factor +D+ is coupled with +E+ in the gametogenesis of rabbits of the constitution +AA BB Ee Dd+. The gametes produced by such animals are of two kinds only viz--+A B E D+ and +A B e d+. When mated with a tortoise aa BB ee dd they give blacks and yellows only--+and no agoutis+. So far as is known, the coupling between E and D is complete. At present this is the only case of coupling between characters yet worked out in a mammal.
[Sidenote: M 3]
Experiments with +Poultry+, illustrating the +recombination of characters+.
Brown Leghorn [F-] × Silky [M-] | (_a_) Coloured (chiefly brown) | (_a_) White plumage (with or plumage | without slight buff tinge) | (_b_) Normal feathers | (_b_) Silky feathers | _________________________|__________________________ | | F_1 [F-] (_a_) Coloured F_1 [M-] (_b_) Normal feathers --------________ ________--------- --------- × --------- | | | F_2 Generation ________________________________________________________ | | | | /------+------\ /------+------\ /------+------\ /------+------\
Coloured plumage Coloured plumage White plumage White plumage Normal feathers Silky feathers Normal feathers Silky feathers
[Sidenote: M 4]
Experiment with +Sweet Peas, illustrating reversion on crossing, followed by the appearance of numerous types in next generation+.
White × White | F_1 Purple | +---------------------+-------------------+ | | | F_2 3 types of purple 3 corresponding figures Whites viz.:-- of reds, viz.:--
(_a_) Purple (_a_) Painted Lady
(_b_) Deep Purple (_b_) Miss Hunt
(_c_) Picotee (_c_) Tinged White
The varied forms in the F_2 generation appear in definite proportions and a certain number of plants of each variety are already "fixed," and have been shewn, by further experiment, to breed true to type.
[Sidenote: M 5]
Experiment with Sweet Peas, illustrating reversion in structural characters.
A cross between the ordinary "Cupid" dwarfs and the half-dwarf "Bush" form results in a complete reversion to the normal tall habit such as occurs in the wild sweet pea. A further generation raised from these reversionary talls consists of talls, Bush, Cupids, and a new form, the "Bush-Cupid." These last combine the erect bush-like habit of growth with the dwarfness of the Cupid.
Bush × Cupid | F_1 Tall | +----------+----+----+------------+ | | | | F_2 Tall Bush Cupid Bush-Cupid
In the ratio 9 3 3 1
[Sidenote: M 6a]
Example of +association of characters in heredity+.
In the sweet pea the dark reddish purple axil is dominant to the light green one. Also the fertile condition of the anthers is dominant to the contabescent sterile condition. In families which involve these characters, the nature of the F_2 generation depends upon the way in which the original cross was made. (A) When each parent has one of the dominant characters.
Dark axil} {Light axil Sterile} × {Fertile | F_{1} Dark axil Fertile | +------------+---+---------+----------------+ | | | | F_{2} Dark axil Dark axil Light axil {[*]Light axil} Fertile Sterile Fertile { Sterile }
Approximate 2 1 1 ratio
* Not yet found, but probably occurs very rarely.]
[Sidenote: M 6b]
(B) If, however, both of the dominant characters go in with one parent, and neither with the other parent, they tend to remain associated in F_{2}; thus:--
Light} {Dark Sterile} × {Fertile | F_{1} Dark Fertile | +-----------+----------+-----------+ | | | | F_{2} Dark Dark Light Light Fertile Sterile Fertile Sterile +Ratio.+ 737 31 31 225
In such a cross the classes resembling the two original parents tend to be produced in excess, while the other two combinations are produced much more rarely. Nevertheless, the ratio of dark to light axil, and of fertile to sterile anthers, is, in each case, a simple 3:1 ratio.
[Sidenote: M 7a]
Example of association of +characters in heredity+.
Purple flower colour is dominant to red in the sweet pea, and the old-fashioned erect form of standard with the central notch is dominant to the hooded. In families where these characters are involved, the nature of the F_{2} generation depends upon the manner in which the cross was made.
(A) When one dominant character goes in with each parent.
Purple} {Red hood} × {erect | Purple erect +--------+-------+-------+ | | | | Purple Purple Red [*]Red erect hood erect hood Approximate ratio 2 1 1
* Not yet found in this mating, but probably occurs very rarely.
[Sidenote: M 7b]
(B) When the two dominants enter, from one parent, they tend to remain associated in the F_{2} generation.
Purple} {Red erect} × {hood | +--------+----+------+--------+ | | | | Purple Purple Red Red erect hood erect hood Approximate \-------+--------/ ratio 3 | 1 These two classes are only found very rarely _i.e._, about once in each 300 plants of the F_{2} generation.
[Sidenote: N & N 1]
Exhibited by the Utah Agricultural College.
* * * * *
Mr. E. G. Titus.
* * * * *
The chart is 147 feet long, 54 inches wide, exclusive of the important data condensed on a separate 8-foot sheet. This is only a preliminary chart, as may be seen from the condensed data attached, which shows that of the 822 persons represented on the chart 539 are of mature age. The unknown persons represent 303, unknown ability; 336, unknown height; 339, unknown weight; 348, unknown health. The family is remarkable for the health of its members, having so far only 97 deaths. The oldest child, Generation II-1, was born in 1827. There are, of course, a large number of persons on the chart who are rather young. Where a person has more than one ability well marked, such as music and literary ability, or music and business ability, or constructive and business ability, the chart shows only one ability. There are several cases where persons have three well marked abilities. In all cases, the following is the rank on the chart:--
Literary ability is always charted. Following this, music and then art, and then constructive. Constructive ability represents those persons who have a decided mathematical and mechanical turn of mind, who are builders, contractors, carpenters of advanced standing, architects and men of these classes. Under "Various" abilities are classified business, agricultural and domestic abilities. These are not marked on the chart.
It will be noticed under "Diseases" that a majority of the persons who have died were infants, and even among infants the deaths are remarkable for their small number considering the conditions under which the people of the third generation of this family had to live. The paternal ancestor, Generation I., came to America in 1842, dying two years later, and his children came to Utah among the early settlers, 1847-52. Many of the third generation were born in this State under conditions that are not by any means comparable to those existing in communities that have been settled for many years. The opportunity to care for children was very limited. Physicians were not as easily reached, and the methods and appliances of modern times were not at hand. Yet, even under these circumstances, it will be noticed of the 822 persons listed on the chart, that only 68 deaths were those of persons under 25 years.
GENERATIONS I IC II IIC III IIIC IV IVC V TOTALS PERSONS CHARTED 1 1 7 18 125 82 384 68 136 822 " OF MATURE AGE 1 1 6 18 118 82 237 68 8 539 --------------------------------------------------------------------- ABILITY--LITERARY 1 5 5 30 6 31 2 1 81 MUSICAL 1 1 9 14 27 1 4 57 ARTISTIC 1 4 2 7 1 15 CONSTRUCTIVE 1 2 2 16 3 15 3 2 44 VARIOUS 1 2 3 36 10 9 61 TOTALS 2 1 11 11 95 35 89 7 7 258 NO SPECIAL ABILITY 3 8 1 2 14 ABILITY UNKNOWN 4 26 65 146 61 1 303 --------------------------------------------------------------------- HEIGHT 5 FT. OR LESS 1 2 3 5-1 TO 5-2 1 3 2 1 2 9 5-3 TO 5-4 1 2 3 8 10 16 40 5-5 TO 5-6 2 14 9 12 2 39 5-7 TO 5-8 2 2 19 4 14 1 42 5-9 TO 5-10 1 1 1 9 2 10 1 25 5-11 TO 6-0 2 16 3 11 3 35 6-1 TO 6-2 3 1 4 1 9 6-3 TO 6-4 1 1 TOTALS 1 1 6 13 72 31 71 7 1 203 UNKNOWN 5 46 51 166 61 7 336 ------------------------------------------------------------------- WEIGHT 100 LBS. OR LESS 2 1 2 2 1 8 101 TO 120 1 10 10 11 1 33 121 TO 150 1 1 6 28 10 27 4 1 78 151 TO 170 1 3 4 23 5 11 6 47 171 TO 200 2 4 7 3 5 6 27 201 TO 220 3 1 4 221 TO 250 1 2 3 TOTALS 1 1 6 17 73 31 58 10 3 200 UNKNOWN 1 45 51 179 58 5 339
GENERATIONS I IC II IIC III IIIC IV IVC V TOTALS HEALTH--EXCELLENT 1 1 6 3 34 15 131 6 44 241 GOOD 7 42 16 54 4 18 141 FAIR 3 3 4 8 18 DELICATE 1 2 4 7 POOR 1 7 2 11 21 TOTALS 1 1 6 15 88 37 208 10 62 428 UNKNOWN 3 24 45 147 58 71 348 ------------------------------------------------------------------- DIED UNDER ONE YEAR 8 16 2 26 1 TO 5 YEARS 1 5 13 1 20 6 TO 25 YEARS 11 11 22 26 TO 40 YEARS 3 3 41 TO 70 YEARS 1 2 5 2 10 PAST 70 YEARS 1 3 4 AGE UNKNOWN 1 2 5 2 1 1 12 TOTALS 1 1 2 7 37 4 41 1 3 97 ------------------------------------------------------------------- CAUSE OF DEATH PREMATURE BIRTH 1 5 6 INFANTILE COMPLAINTS 1 11 13 3 28 DIPHTHERIA 3 5 8 SCARLET FEVER 2 2 MEASLES 1 1 TYPHOID FEVER 2 2 4 PNEUMONIA 1 6 1 1 9 CONSUMPTION 2 2 OPERATIONS 1 1 CHILD BIRTH 1 1 2
VARIOUS 1 1 6 6 9 23 UNKNOWN 1 3 3 3 1 11 TOTALS 1 1 2 7 37 4 41 1 3 97
[Sidenote: O]
Exhibited by the Eugenics Education Society.
O 1 Mendelism.
[Sidenote: O 1a]
Theoretical Example of Mendelian Inheritance in Peas. (After _Thomson_.)
[Sidenote: O 1b]
Theoretical Example of Mendelian Inheritance in Peas. (After _Laurie_.)
[Sidenote: O 1c]
Theoretical Example of Mendelian Inheritance, with Dominance, in Mice. (After _Laurie_.)
[Sidenote: O 1d]
Illustration of the Theory of Gametic Purity in Mendelian Heredity in Mice. (After _Laurie_.)
[Sidenote: O 1e]
Example of Mendelian Inheritance, without Dominance, in Blue Andalusian Fowls. (After _Laurie_.)
[Sidenote: O 1f]
Illustration of the Theory of Gametic Purity in Mendelian Heredity, in Blue Andalusian Fowls. (After _Laurie_.)
[Sidenote: O 2]
Standard Scheme of Descent. (After _Galton_.)
[Sidenote: O 3]
Comparison of Mr. Booth's Classification of All London with the Normal Classes. (After _Galton_.)
[Sidenote: O 4]
Descent of Qualities in a Population. (After _Galton_.)
[Sidenote: O 5]
Inheritance of Ability, as exemplified in the Darwin, Galton, and Wedgwood Families. (After _Whetham_ and _Marshall_.)
[Sidenote: P]
Exhibited by the American Breeders' Association--Eugenics Section.
C. B. Davenport, Esq.
[Sidenote: P 1-16]
Charts of Statistics of Defectives.
Charts of Classification of Defectives.
Charts of Principles of Heredity.
Pedigrees collected by field-workers in America.
[Sidenote: Q]
Exhibited by Cyril Burt, Esq.
Description of Diagrams illustrating the use of experimental Tests of Mental Capacities.
1. "Experimental Tests of General Intelligence."
[Sidenote: Q 1]
A List of twelve tests applied to two schools at Oxford. The first two columns of figures indicate the "reliability" or self-consistency of the tests as compared with that of examinations and master's general impression. The second two columns give the correlations of the results of the tests with the children's "general intelligence." It will be seen that several of the tests of higher mental processes are as reliable as the scholastic tests at present in vogue, and that they correlate quite as highly with intelligence. Further experiments show that while examinations and master's estimates measure knowledge and skill acquired by memory and training, the tests seems to provide measurements rather of innate capacities; and that children of superior parentage (_e.g._ the preparatory school boys) are themselves superior at tests, which show an appreciable positive correlation with intelligence (_i.e_. all except tests of touch and weight). The tests thus provide an experimental demonstration of the inheritance of mental ability and a means of measuring the same. (References:--Burt, Experimental Tests of General Intelligence, British Journal of Psychology, Vol. III., Pts. 1 and 2.) Burt, Inheritance of Mental Characteristics, Eugenics Review, 1912, July.
[Sidenote: Q 2]
2. Sex-differences in mental tests.