ArousT 22, 1919] 



SCIENCE 



183 



■ The University of Bristol has made the fol- 

 lowing appointments to the professorial chairs 

 mentioned: Botany: Dr. Otto Vernon Darbi- 

 shire, lecturer in botany in the university. 

 Education: Dr. Helen Marion Wodehouse, 

 principal of the Bingley Training College, 

 Yorkshire. Henry Overton Wills Chair of 

 Mathematics: Dr. H. Eonald Hasse, late fel- 

 IW of St. John's College, Cambridge; senior 

 lecturer in mathematics in the University of 

 Manchester. Mechanical Engineering : Major 

 Andrew Robertson. Henry Overton ^VUls 

 Chair of Physics: Dr. Arthur Mannering 

 Tyndall, acting head of the department of 

 physics in the university during the war. 

 Henry Overton Wills Chair of Physiology : 

 Dr. George A. Buckmaster, assistant professor 

 of physiology in the University of London. 



DISCUSSION AND CORRESPONDENCE 



TANDLER AND KELLER ON THE FREE- 

 MARTINI 



In April, 1916, the writer published a short 

 article on "The Theory of the Free-Martin "- 

 iii which he sought to demojistrate that con- 

 trary to the then prevailing opinion the free- 

 martin is a female, and that its intersexual 

 condition is due to early embryonic anasto- 

 mosis of the blood vessels of its chorion with 

 those of the male twin, with consequent in- 

 version, more or less complete, of the internal 

 organs of reproduction by action of the testi- 

 cular homones of the male. A detailed ac- 

 count of the data and theory was published 

 in the Journal of Experimental Zoology in 

 1917.^ At the time of publication the writer 

 supposed that both the data and theory were 

 new, but he has learned this summer by a 

 reference in a work of Magnusson* that some 

 of the data at least- were anticipated by Tand- 



1 To the kindness of Professor A. Lipschutz, of 

 Berne,_ the writer owes a reference to a later and 

 piresumably more complete account of the investi- 

 gations of the same authors (Wiener Tierijrzlitche 

 Wochemchrift, III., Jahrgang, Heft 12, 1916), 

 which however he has not yet seen. 



2 Science, N. S., XLIII., pp. 611-613. 



3 Vol. 23, pp. 371-452. 



* Aroh. f. A7iat. n. Physiol., Anat. Abt., 1918, 

 pp. 29-62. 



ler ■ and ■ Keller in a publication dating from 

 1911.5 



These writers studied seventeen pairs of 

 two-sexed cattle twins in fcetal stages and 

 determined the following fundamental facts: 



1. That such twins have a common chorion. 



2. That branches of the umbilical vessels, 

 especially the arteries, anastomose by rela- 

 tively large branches, so that an injection 

 from an mnbilical artery of one tretus would 

 pass over into the umbilical arteries of the 

 other. The females of such pairs possessed 

 the typical "hypoplastic genitals^' of the 

 free-martin. 



3. In one ease, in which there was no macro- 

 scopic vascular anastomosis in the chorion 

 and tlie- injection would not pass over, both 

 male and female possessed normal repro- 

 ductive organs. The authors consider this' 

 more than a mere matter of chance. 



4. That the maternal ovaries possess two 

 corpora lutea, usually one in each ovary ; 

 hence they correctly interpret the twins as 

 dizygotic. 



5. The youngest pair of twins examined had 

 a neck-rump measurement of 21 cm.; tie 

 female was typically malformed. Hence the 

 origin of the condition is earlier. 



From these facts the authors conclude that 

 "vascular relationships and genital develop- 

 ment stand in some kind of etiological rela- 

 tionship." 



The writer independently stated all of these 

 facts in his 1916 paper, and in addition the 

 following facts and considerations : 



1. A comparison of sex ratios of the four 

 kinds of twins c?c?, 99, c??, (^, demonstrating 

 from the statistics that the sterile free-martin 

 must be zygotically female. 



2. A study of much earlier stages than the^ 

 youngest of Tandler and Keller showing that 

 the union of- chorions is secondary and that it 

 probably occurs at or about the time of begin- 

 ning sex-differentiation (20-25 mm.). 



3. A statement of conditions of the foetal 

 membranes . in twins of sheep, showing that, 

 though the membranes fuse, no macroscopic 



■ 5 DeirtscJie tieriirztUehe WoeheiiscJinft, 19 Jahr-'' 

 gang, 1911, pp. 148-149.' > 



