Decembek 30, 1921] 



SCIENCE 



663 



sider methods by which, the acquisitive in- 

 stinct in children may be diverted by en- 

 couragement and suggestion so as to prove 

 tbe stimulus for the higher forms of intel- 

 lect. 



William Drumm Johnston, Jr. 

 Walkeb Museum, Universitt op Chicago 



linkage in poultry 



Two genes each of which is sex-linked must 

 obviously be completely linked in the gameto- 

 genesis of the sex which is heterozygous for the 

 sex gene. On Morgan's theory of inheritance 

 they should also be partially linked in the 

 homozygous sex, as in the female of Droso- 

 phila. I therefore decided to test for linkage 

 between two well-known sex-linked genes of 

 poultry, namely B, whose presence causes bar- 

 ring of melanic feathers, and S, which by in- 

 hibiting yellow pigmentation, converts " gold " 

 into " silver " hackle feathers. A Brown Leg- 

 horn cock of composition bs/bs was therefore 

 mated to Barred Plymouth Rock hens of com- 

 position BS. Their male children were of com- 

 position BS/bs. These were mated to bs Brown 

 Leghorn hens, and have so far produced: 



30 Barred silver BS/bs ^ and BS 2 



17 Unbarred silver bS/bs ^ and bS ? 



10 Barred gold Bs/bs c? and Bs ? 



21 Unbarred gold bs/bs j? and bs 5 



This corresponds to a series of spermatozoa 

 30 BS, lY bS, 10 Bs, 21 bs, or 27 cross-overs 

 out of Y8. The cross-over value is therefore 

 34.6 per cent, with a probable error of 3.6 per 

 cent., that is to say there is undoubtedly link- 

 age. The numbers of barred and unbarred are 

 practically equal, but there is a 50 per cent, ex- 

 cess of silver over gold, perhaps due to selective 

 mortality. 



The experiment is being continued, and it is 

 hoped next year to obtain repulsion as well as 

 coupling. If Pearl is correct in his view that 

 one of the genes for high egg-laying is carried 

 in the sex-chromosome, the economic impor- 

 tance of mapping it is considerable. For ex- 

 ample if the locus of the egg-laying gene L^ 

 lies between those of B and S, then if B and S 

 have been transferred together from a race of 

 high-laying power to one of low-laying power, 

 we shall know without further testing that, ex- 



cept in the rare cases of double crossing-over, 

 Lj has been transferred with them. 



J. B. S. Haldane 

 New College, 

 Oxford, England 



the zoological record 



The Zoological Record, which was founded 

 in 1864 by English zoologists, has been issued 

 regularly ever since and contains each year 

 a complete bibliography of all publications 

 connected with zoology. It is now the sole 

 work of the kind, and is invaluable to all 

 workers in every branch of zoology. 



Previous to 1914 The Zoological Record 

 formed part of the " International Catalogue 

 of Scientific Literature," and was issued under 

 the joint responsibility of the Royal Society 

 and the Zoological Society. As the Royal 

 Society found itself unable to proceed with 

 the volumes of the " International Catalogue " 

 after the issue for 1914, the Zoological 

 Society has undertaken to prepare and issue 

 the volumes for 1915-1920 inclusive at its 

 sole financial risk. 



It is the wish of the record committee of 

 the Zoological Society to continue the publi- 

 cation of this most useful work, but it is 

 obvious that they can not expect the Society 

 to undertake the heavy financial liability in- 

 volved in publication unless they receive 

 reasonable support from working zoologists 

 both at home and abroad. 



I hope, therefore, that all working zoolog- 

 ists who agree with me that the suspension 

 of the publication of the Record would have 

 a most disastrous effect on the progress of 

 zoology, will either subscribe themselves or 

 will urge the librarians of the institutions 

 with which they are connected to do so. 



A prospectus and form of subscription 

 either for the whole or separate divisions of 

 the Record can be had on application to the 

 Zoological Society. W. L. Sclater, 



Editor 



Zoological Society op London, 

 London, N. W. 8 



meteorologische zeitschrift 

 In a letter received from Professor V. Con- 

 rad, the recently elected secretary of the 



