498 REFERENCES

[54] Davey, C. M. (1926), ' Group, Verbal and Pictorial Tests of

Intelligence/ Brit.J. Psych., XXVI, pp. 1-20.
[55] Thomson, G. H., and Bailes, S. (1926), < The Reliability of

Essay Marks,' Forum of Education, IV, pp. 85-96.
[56] Spearman, C. (1927), The Abilities of Man : Their Nature and

Measurement (London : Macmillan).
[57] Thomson, G. H. (1927), ' The Tetrad Difference Criterion,'

Brit. J. Psych., XVII, pp. 235-55.
[58] Hargreaves, H. L. (1927), * The Faculty of Imagination,'

Brit. J. Psych. Mon. Supp.9 No. 10.
[59] Pearson, K., and Mod, M. (1927), c The Mathematics of

Intelligence, I. Sampling Errors in the Theory of a

Generalized Factor,' Biometrika, XIX, pp. 246-91.
[60] Kelley, T. L. (1928), Cross Roads in the Mind of Man (Stanford

University Press).
[61] Dodd, S. C. (1928), 'The Theory of Factors/ Psych. Rw.,

XXXV, pp. 211-34, 261-79.

[62] Howland, R. (1928), Phil. Mag. (Ser. vii), VI, pp. 839-42.
£63] Spearman, C. (1928), £ Pearson's Contribution to the Theory

of Two Factors,' Brit. J. Psych., pp. 95-101.
[64] Wilson, E. B. (1928), c On Hierarchical Correlation Systems,*

Proc. Nat. A cad. Sc.9 XIV, pp. 283-91.
[65] Turnbull, H. W. (1928), The Theory of Determinants, Matrices

and Invariants (London : Blackie).
[66] Mackie, J. (1928),'The Sampling Theory as a Variant of

the Two-Factor Theory,' J. Educ. Psych., XIX, pp.

614-21.
[67] Spearman, C. (1930), c G and After: a School to end

Schools,' ap. Psychologies 0/1930, pp. 339-66,
[68] Hokinger, K, J. (1930), Statistical Resume of the Spearman

Two-Factor Theory (Chicago: Univ. Chicago Press).
[69] Btirt, C. (1931), af. Report of Consultative Committee of the

Board of Education on The Primary School, Appendix III

(London : H.M. Stationery Office),

[70] Stephenson, W. (1931), ' Tetrad Difference for Verbal Sub-
Tests relative to Non-Verbal Sub-Tests,' J. Educ* Psych.,
• XXII, pp. 334~5°-
[71] Weyl, H. (1931), The Theory of Groups and Quantum

Mechanics (London : Methuen),
[72] Tryon, R. C. (1932),c So-called Group Factors as Determiners

of Ability,' Psych. Rw., XXXIX, pp. 403-39.
[73] Turnbull., H. W., and Aitken, A. C, (1932), Introduction to the

Theory of Canonical Matrices (London : Blackie)*