252 



SCIENCE 



[N. S. Vol. LIV. No. 1394 



have gained from coking. The results of our 

 awakening are shown in the newly issued 

 summary of the 1920 census. In 1914 the 

 United States had 754 establishments manu- 

 facturing chemicals, with products worth 

 $200,195,800. In 1920 it had 1,374 establish- 

 ments, with products worth $694,643,000. The 

 increase in the value of the products in six 

 years was 247 per cent. The manufacture of 

 potash and potassium products was slightly 

 more than twice as great — measured in value 

 — as in 1914; that of acids about two and a 

 half times as great; that of sodas and sodium 

 almost three times as great, and that of coal 

 tar products was $133,340,000, as against 

 $8,839,000 in 1914, or about fifteen times as 

 great. 



Gratifying as this progress is, the complex- 

 ity of some essential chemical industries, the 

 careful adjustments they must establish with 

 other industries, render more progress neces- 

 sary before we are safe. Leaders in the coal- 

 tar business, which are vital to national de- 

 fence, declare that although we have far 

 surpassed all other nations except Germany 

 and Switzerland, we need five years yet to 

 make our position impregnable. For the 

 time being many of our drug-making and 

 dye-making firms — we had 213 companies 

 making these and other coal-tar products 

 last year — have a right to complete tariff pro- 

 tection. The chemists at Columbia Univer- 

 sity have adopted resolutions asking for a 

 " selective embargo." Any embargo needed 

 in certain parts of this field can and should 

 be provided by wise tariff legislation, and 

 not, as some demand, by the arbitrary decrees 

 of a licensing bureau. — New Yorh Evening 

 Post. 



SPECIAL ARTICLES 



TRIPLOID INTERSEXES IN DROSOPHILA 

 MELANOGASTER i 



In an experiment made to determine the 

 locus of the new second-chromosome recessive 

 mutant " brown " by means of a back-cross 

 with the well-known second-chromosome re- 

 cessives plexus and speck, one culture was 



1 Paper read before the Pacific Division A. A. 

 A. S., Univ. of Cal, Aug. 5, 1921. 



found that produced a total of 96 females, 9 

 males, and about 80 individuals that were 

 intermediates between males and females. 



The " intersexes," which were easily distin- 

 guished from males and from females, were 

 large-bodied, coarse-bristled flies with large 

 roughish eyes and scolloped wing-margins. 

 Sex-combs (a male character) were present 

 on the tarsi of the fore-legs. The abdomen 

 was intermediate between male and female in 

 most characteristics. The external genitalia 

 were preponderantly female. The gonads were 

 typically rudimentary ovaries; and sperma- 

 thecse were present. !N"ot infrequently one 

 gonad was an ovary and the other a testis; 

 or the same gonad might be mainly ovary 

 with a testis budding from its side. The in- 

 tersexes showed considerable variation, ap- 

 parently forming a bimodal group — on the one 

 hand a more " female-type," the extreme in- 

 dividuals of which might even lack sex-combs, 

 and, on the other hand, a more " male-type," 

 many of the individuals having large testes 

 and normal male genitalia. All intersexes 

 proved sterile. 



Just as striking as the production of inter- 

 sexes was the fact that the 96 females and 9 

 males of that same culture showed three, in- 

 stead of two, large classes representing origi- 

 nal combinations, namely, plexus speck, plexus 

 brown, and brown speck. Extensive tests were 

 made of these flies; and each was found to 

 have received from the father a second-chromo- 

 some carrying jilexus brown and speck, and to 

 have received from the mother one of three 

 different second-chromosomes, namely, a plexus 

 brown, or a plexus speck, or a brown speck 

 chromosome. That is, the mother of the in- 

 tersexes had carried three second-chromosomes, 

 instead of two. For each of the loci plexus, 

 brown and speck she had carried two recessive 

 genes for the mutant character and one wild- 

 type allelomorph, with nearly complete domi- 

 nance of the wild-type gene in each case. 



A condition of triploidy for certain sections 

 of chromosome had been met with in the pre- 

 vious (unpublished) studies on duplications 

 and on translocation; but that this triploidy 

 was far more extensive soon became evident. 



