June 30, 1922] 



SCIENCE 



703 



of no scientific body and absolutely unknown 

 in scientific circles, has in at least one of his 

 contributions to the religious press (the one in 

 which he tried to make much of the so-called 

 anti-evolution admissions of Bateson) had the 

 eifrontery to style himself "geologist," in the 

 expression he there used "we geologists"; and 

 this is the man who in his support of a literal 

 Grenesis is hailed by the "Fundamentalists" as 

 their great champion — one who has "demon- 

 strated the absurdity of the evolutionist's 

 geological theories" and has brought into prom- 

 inence the "heretofore mute evidence of a 

 mighty upheaval and a flood." 



Arthuk M. Miller 

 unrveksitt of kentucky 



KEYS IN SYSTEMATIC WORK 



To THE Editor of Science: It seems more 

 mechanical uniformity is possible in the keys 

 which systematists find of so much value in 

 descriptive work. The number of forms used 

 now is limited apparently only by the num- 

 ber of authors publishing such keys, and among 

 this large number of forms are many which 

 are wasteful of space and many which are 

 confusing to the student. 



Some of the mechanical requirements of a 

 good key may be briefly summarized: 



1. The key should occupy a minimum 

 amount of space, and should present the mini- 

 mum difiiculty to the printer. 



2. The key should be capable of indefinite 

 expansion, that is, provide for any number of 

 groups, and no headings of groups or sections 

 should be duplicated. 



3. Any desired space under each heading 

 should be availa.ble. 



4. Coordinate groups in the key should be 

 recognizable as such at a glance and such co- 

 ordinate groups should be in juxtaposition. 



5. The key should be as readily "run back- 

 ward" as "run forward." 



Ample reasons for all these requirements 

 could be given but need not be detailed here. 

 The following skeleton key shows a form which 

 I believe meets all these requirements, and it 

 is presented for criticism in the hope that after 

 discussion some form of key may be found 

 which will meet with general approval. Sec- 



tions 3 and 3' show length of printed lines 



when several Unes are required for a section. 



Key to Species a-h of the Genus X 



1. Tarsi spurred 2. 



1'. Tarsi not spurred 5. 



2 (1) a. 



2'- 3. 



3 (2') 



4. 



3'. 



6. 



i (3) c. 



4' d. 



5 (1') e. 



5' 6. 



6 (5') /. 



«' <7. 



6" h. 



E. B. Williamson 

 Bluffton, Indiana 



THE Y-CHROMOSOME TYPE OF SEX- 

 LINKED INHERITANCE IN MAN 



In a short article which appeared in the 

 Journal of Heredity for November, 1921, 

 Richard Schofleld describes a case of human 

 inheritance which has very gi-eat theoretical 

 interest. It involves the transmission through 

 four generations of a condition called webbed 

 toes. The condition is found only in male 

 members of the family and is transmitted from 

 father to son, never to a daughter nor through 

 a daughter to her sons. 



It thus has the distribution in heredity of a 

 Y-chromosome, a structure found only in the 

 male-determining spermatozoa of certain ani- 

 mals and never in their eggs. The Y-chromo- 

 some accordingly is a structure possessed by 

 male individuals only and thus forms an ap- 

 propriate vehicle for the transmission of char- 

 acters from father to son, quite independently 

 of the female line of descent. All this was 

 pointed out by Schmidt in a contribution from 

 the Carlsberg Laboratory, which I reviewed in 

 Science for April 8, 1921, under the title 

 "A New Type of Inheritance." Schmidt 

 described in a fish the first known case of 

 inheritance of this type. This has since been 

 eonflnned in the case of another species of fish 

 by a Japanese observer, so that it may now be 

 regarded as well established. Schofield's article 



