never both of these sex elements. As A FUNCTIONAL Y-CHROMOSOME? a result of this segregation, the That the Y-chromosome probably spermatozoa, when they are finally carries a gene for the black spot on formed, will carry either a "Y" or the dorsal fin of the little fish Libestis male-determining element, or an X reticulatus is demonstrated by Winge or female-determining element, but it of the Genetic Laboratory of the Royal is impossible for such a spermatozoön Veterinary and Agricultural College, to carry both. If a spermatozoön car- Copenhagen, in Journal of Genetics rying a Y-chromosome fertilizes an for October. This male spot passes egg, the sex will be male. Conversely, through the generations confined to if a spermatozoön carrying an Xchromosome fertilizes an egg the sex character. It is not quite clear, howwill be female.

the male sex-thus it is a sex-limited

ever, that the inheritance of the black spot is different from that of the beard in man; and the factor for this quality can reside in the female gam

The discrepancies found in earlier studies on the questions of chromosome numbers and sex determination were probably due, as we now view etes. the matter, in part to an inadequate technique, but mainly to the use of tissue, such as that obtained from executed criminals, where the testes! have remained in the body for half just now in the origin and probable

an hour after the death of, the indi

vidual. During this delay the sensitive germ cells, apparently, undergo a certain amount of necrosis which

results in more or less fusion of the chromosomes. When perfectly fresh material is used, together with an adequate technique, a complete study of the chromosomes can be made.

On the basis of this study, we may answer now, without hesitation, the two questions stated at the beginning

of this note. The number of chromo

somes in man is 48 (diploid or somatic number) and sex is determined in man, at the moment of fertilization, just as it is in insects, it being simply a matter of which type of spermatozoön fertilizes the egg. Since the Xcarrying and Y-carrying spermatozoa are equally as numerous, there is in man a 50-50 chance in favor of either sex. There is no way known in which this ratio can be modified.

THE EVOLUTION OF MAN. There is a great popular interest

fate of the human species. Very
timely, accordingly, is a collection of
essays on human evolution by stu-
dents of its different phases. Professor

R. S. Lull contributes a brief, but up-
to-date summary of our knowledge
of prehistoric man. Dr. H. B. Ferris
describes human embryological devel-
opment and variation. Professor G. H.
Parker writes briefly of the nervous
system and its history. President
in the evolution of intelligence.
J. R. Angell discusses some problems

Dr.
A. G. Keller considers "Societal Evo-

66

"

lution" and the origin of the "mores.
Professor Conklin treats of the
Trend of Evolution" and the con-
sequences of reduced fecundity of the
better-endowed classes and the pro-
tection of the race from the action
of selective elimination. These are all
interesting essays, by thorough schol-
ars and, as such, deserve to be widely
read.

The Evolution of Man.
delivered before
Chapter of the Sigma Xi.
Yale Univ. Press. 1922.

The completer account of this work lectures is now in press.

A series of the Yale New Haven: 202 pp. $3.00.

EUGENICAL NEWS INDEX

VOLUME VII., 1922

Ashley, Dr., 87.

Babbott, Frank L., 90, 91.

Baehr, Dr. Edmund M., 91.

Cannizzaro, 67.

Cannon, Gertrude E., '10, 12.
Carlisle, Dr. Chestér. L., 92.
Carpentier, Georges, 124.
Cassatt, A. J., 103.
Catlin Mark, The, 51.
Cavendish, 67.

Cestre, Prof. Charles, 47.
Chambers, Lady, 2.
Chapin, F. Stuart, 113.
Chapin, Gilbert, 104.
Cheney, Dr. C. O., 115.
Clark, Mary, '13, 12.

Clark, Rosamond, 81.

Clark, Willis, 12, 127.

Cockerell, Dr. T. D. A., 62.

Conklin, E. G., 119.

Coley, Dr. William, 115.

Bagg, Mrs. Halsey J. (See Osborn, Dorothy, Cook, Dr. W. P., 71.

'16), 119.

Baldwin, 86.

Baldwin, Dr. Bird T., 91.

Barber, Col. E. C., 115.

Barker, Lewellys F., 60, 77, 91.

Barlow, Deborah, 12.

Barrett, Mrs. Janie, 96.

Barris, Elizabeth L., '13, 12.

Bauer, E., 97.

Baur, Dr. Erwin, 121.

Bayet, Dr., 120.

Beekley, Catherine W., '13, 12.

Bell, Alexander Graham, 64, 93.
Belzer, Katherine, '22, 112.
Benedict, 86.

Benjamin, Dr. Harry, 60, 70.
Bergauer, V., 61.

Berman, Dr. L., 1.

Berry, William, D., 96.

Berryer, M., 120.

Berthollet, Dr., 117.

Berzelius, 67.

Bethel, Ellsworth, 62.

Billings, Dr. W. C., 114.
Blauw, A. H., 114.

Boas, Dr. Franz, 100, 133.
Book, W. F., 10.

Boulenger, Dr. M. F., 120.
Boyle, 67.

Bragg, William, 11.
Bramwell, S. S., 122.
Brehovsky, Mary J., 12.
Briggs, L. V., 97.
Brooks, Mary, 103.
Brooks, William, 103.
Broome, Mrs. Emilia, 121.
Browne, Sir Thomas, 16.
Brožek, Dr. Arthur, 121.
Bruce, H. A., 49.
Brunet, M., 120.

Buchanan, J. A., 67.

Bucknell, Lydia E., 22, 112.

Burnham, Dr. A. C., 56, 69.

Burroughs, Nannie H., 96.

Caldwell, Dorothy W., 18, 61.
Campbell, Mary (Dranga), '10, 12.
Canavan, Dr. Myrtelle M., 60, 81.

Corry, Miss E., 2.

Cosentini, Prof. Francesco, 114.

Cotter, J. S., 100.

Covert, Mildred S.. '17 (see Hollister, Mrs.

Scoville E.), 119.

Cowan, Samuel K., 103.

Cowdery, Karl M., '15, 127.

Crane, Dr. Harry W., '15, 13, 52.
Crookes,

Crum, 86.

67.

Cutler, Dr. Ira A., 62.

Czolgosz, 97.

Dahlberg, Mrs. G., 121.

Dalton, 67.

Danforth, Dr. C. H., 112.

Darwin, Major Leonard, 2, 14, 117, 123.
Davenport, Charles B., 14, 20, 60, 85, 91,
112, 113, 117.

Davy, 67.

Dawes, Dr. Spencer L., 60, 86.

Dealey, William L., '13, 13, 119.

Decroly, Prof., 14.

Dederer, Dr. Pauline H., '22, 112.
Delfino, Dr. V., 14, 41.
Demoor. Prof.. 120.
Dempsey, Jack, 124.

Derby, Mary Jane, 43.

Detlefsen, Dr. J. A., 119.

Devitt, Saidee, '10, 104.

Diakonoff, Michal, 13.

Dight, Dr. Charles F., 63, 91.

Dom, M., 120.

Downey, Dr. June E., 11.

Drachovsky, Dr., 61.

Draper, Dr. J. W., 131.

Dublin, Dr. Louis I., 8.

Dunlap, K., 59.

Earle, Mabel L., 4, 12, 44, 52, 84.

Edel, Dr. W., 122.

Edwards. Ancestors of Maj. Gen. Clarence
R., 104.

Edwards, Hon. Bulkeley & His Desc., 104.

Edwards, Desc. of Alexander, 104.

Edwards, Desc. of John, 104.

Edwards, Dwellyn Nathaniel, 104.

Edwards Family, Jonathan, 104.

139

Estabrook, Dr. A. H., '10, 43, 46, 70, 108, Hultkrantz, J. V., 121.

Govaerts, Dr. Albert, 14, 64, 92, 117, 120. Landsteiner, W.. 67.

Csborn, Dorothy, '16 (see Bagg, Mrs. Hal- Smith, Mrs. Carrie W., 48.

Paton, Dr. Stewart, 89, 91.

Peabody, Ephraim, 43.

Pearson, Dr. Mabel Hattersley, '10, 4.

Perry, Elizabeth H., '16 (see Herman, Mrs.