242 



SCIENCE 



[N. S. Vol. XXXII. No. 81G 



nounced: Francis H. Slack, M.D. (Tufts), 

 director of the laboratories of the Boston 

 Board of Health, to be professor of bacteriol- 

 ogy; J. S. Hughes, A.M. (Ohio), to be assist- 

 ant in chemistry, and C. H. Clevenger, A.M. 

 (Chicago), and Edward Bartholow, A.B. 

 (Kansas), to be assistants in mathematics. 



The Journal of the American Medical As- 

 sociation states that considerable dissatisfac- 

 tion has been manifested in the medical and 

 lay press of Hungary toward the appointment 

 of Dr. L. Nekam to the chair of dermatology 

 in the University of Budapest on the recom- 

 mendation of Count Fichy, minister of public 

 instruction, whose appointment has been sanc- 

 tioned by Emperor Francis Joseph. The com- 

 mittee of the medical faculty had proposed the 

 names of Drs. Torok and Marschalko, to the 

 general board whose duty it was to investigate 

 and report on the applicants. This body en- 

 trusted this duty to a theologian, who ignored 

 the proponents of the medical faculty and ap- 

 pointed Dr. Xekam, with the resulting dissat- 

 isfaction. 



It is announced that a national office of 

 French universities and schools has been in- 

 augurated under the presidency of M. Paul 

 Deschanel, of the French Academy. Professor 

 Paul Appell, of the University of Paris, and 

 Professor Georges Lyon, of the University of 

 Lille, have been elected vice-presidents and Dr. 

 Raoul Blondel has been appointed director. 

 The new department is to be installed at the 

 Sorbonue, and its object will be to make 

 known to foreigners the educational resources 

 of France. 



DISCUSSION AND CORRESPONDENCE 



SELECTIVE FERTILIZATION AND THE RELATION OF 

 THE CHROMOSOMES TO SEX-PRODUCTION 



Explanations as to what one has really 

 said or meant make dull reading, but are 

 sometimes pardonable in the interest of ac- 

 curacy. Some one has said (was it W. K. 

 Clifford?) that there are some' subjects con- 

 cerning which it is often difficult to be sure 

 what others mean, and not always easy to be 

 sure what one means oneself! Perhaps se- 



lective fertilization and its relation to the 

 " sex-chromosomes " is one of these. At any 

 rate, I find with some surprise that a number 

 of recent writers seem to regard me as an ad- 

 vocate of a conception that I have from the 

 first held to be improbable. The hypothesis of 

 selective fertilization (with all that it implies) 

 may be true, but it is not true that I have 

 anywhere, to my knowledge, maintained or 

 advocated it. On the contrary, already in the 

 second of my " Studies on Chromosomes " 

 this hypothesis was characterized as " a priori 

 very improbable" (1905, p. 539), and I have 

 since steadily sought to find an interpretation 

 of the cytological facts that would not in- 

 volve such a way of cutting the Gordian knot 

 of the sex-problem. 



In my third '"Study" (1906), where this 

 question was first fully considered, I suggested 

 for purposes of analysis, two possible ways of 

 interpreting the observed facts, but advocated 

 neither owing to insufficiency of data. The 

 first (characterized, rather unluckily, as the 

 " Mendelian interpretation"), assumed, "for 

 the purpose of analysis," that " the two sex- 

 chromosomes, which couple in synapsis and 

 are subsequently disjoined by the reducing 

 division, are respectively a male-determinant 

 and a female-determinant " — i. e., that the 

 two bear opposing or alternative male- and 

 female-determining factors or " genes." An- 

 alysis brought out the fact that this as- 

 sumption led to selective fertilization as a 

 necessary corollary. But even in my first 

 preliminary paper (1905) it was pointed out 

 that this interpretation encountered '' great, 

 if not insuperable difficulties." Regarding 

 this, the third " Study " states, " It has not been 

 my intention to advocate the foregoing inter- 

 pretation, but only to set forth as clearly as 

 possible the assumptions that it involves " 

 (p. 33). Admitting that it " might in fact 

 give the true solution of the problem," I 

 nevertheless " endeavored to seek for a dift'erent 

 interpretation that might escape the necessity 

 for assuming selective fertilization" (p. 33). 

 The second interpretation, representing such 

 an attempt, was based on the quantitative re- 



