502 



SCIENCE 



[N. S. Vol. L. No. 1300 



Drummondi has recently tested the pos- 

 sibility of carotin being the fat-soluble 

 vitamine by feeding both crude and crystal- 

 line preparations of the pigment to rats, al- 

 though the question may be raised as to the 

 logic of testing the relation to fat-soluble 

 vitamine of a substance of which is not nat- 

 ural to the body of the animal upon which the 

 test is performed. Carotin is not found in 

 the body of the rat. 



The writer^ has recently reported the fact 

 that it is possible to raise a flock of chickens 

 from hatching to maturity on a diet free, or 

 at most containing the merest traces, of 

 carotinoids. Not only did the mature hens 

 lay eggs whose yolks were free from caroti- 

 noids, but a second generation of carotinoid- 

 free chicks were hatched from them. Only 

 one of two possible conclusions can be drawn 

 from this experiment. Either the fat-soluble 

 vitamine and the yellow plant pigments are 

 not related physiologically or the fat-soluble 

 vitamine requirement of fowls differs from 

 that of mammals. The diet which we used 

 for the successful growth of the chickens con- 

 tained an abundance of fat-soluble vitamine, 

 however, in the form of carotinoid-free pork 

 liver. 



Another interesting case of negative rela- 

 tion between carotinoids and fat-soluble 

 vitamine is seen in the fact that a number of 

 species of animals, such as sheep, swine, dogs, 

 cats, rats, rabbits, and guinea pigs are free 

 from carotinoids in blood^ and adipose tissues, 

 and nerve cells.^ The milk fat of the 

 mammals of these species is also colorless. 

 How is one to make the successful raising of 

 young on carotinoid-free milk coincide with 

 the assumption that fat-soluble vitamine is 

 one of the yellow plant pigments? 



Still another instance of negative relation 

 between carotinoids and fat-soluble vitamine 

 is seen in the case of certain vegetable oils, 



1 J. C. Drummond, Biochem. Jour., XIII., 81, 

 1919. 



2 L. S. Palmer and H. L. Kempster, Jour. Biol. 

 Chem., XXXIX., 299, 1919. 



3L. S. Palmer, Jour. Biol. Cltem., XXVII., 27, 

 1916. 



* D. H. Dolley and Frances Guthrie, Science, 

 N. S., L., 190, 1919. 



like cottonseed oil. Fresh cottonseed oil, after 

 being purified from resinous material, has a 

 beautiful golden yellow color and is rich' in 

 carotinoids. It should also contain an abun- 

 dance of fat-soluble vitamine to be in keep- 

 ing with Steenbock's assumption. Apparently 

 this is not the case since both bleached and 

 unbleached cottonseed oil has been found to 

 be free from vitamine.^ The oil from yellow 

 corn, similarly, should contain the vitamine, 

 but the same investigation^ has reported 

 failure to obtain growth with diets contain- 

 ing the commercial unbleached corn oil. 



It is thus possible to cite a number of 

 instances where the probable relation between 

 carotinoids and fat-soluble vitamine breaks 

 down. No doubt others could be found. The 

 writer regards the instances of a simulta- 

 neous occiu'rence of fat-soluble vitamine and 

 plant carotinoids as fortuitous. The similar- 

 ity of certain of the properties of the two 

 kinds of material admittedly offers a work- 

 ing basis for the idtimate isolation of the fat- 

 soluble vitamine, and research in this direc- 

 tion offers many fascinating possibilities. 

 The relation between the vitamine and color 

 in the case of corn may be a genetic one, in 

 which case it should be possible to transfer 

 the vitamine to white corn. Further at- 

 tempts, however, to establish an identity of 

 the vitamine with one of the carotinoid pig- 

 ments is not likely to lead to profitable 

 results. Leroy S. Palmkr 



Section of Daiky Chemistey, 

 Division op AGEicDLruRAL Biochemistry, 

 University op Minnesota 



SCIENTIFIC ARTICLES 



WOUND HEALING IN EXPERIMENTAL 

 (CELLFIBRIN) TISSUE' 



1. If we make a defect in the skin, processes 

 of healing set in which in time lead to a 

 closure of the wound. Primarily, the defect 



5L. S. Palmer and C. H. Eckles, Missouri Agr. 

 Exp. Sta. Ees. Bull. 10, 361, 1914. 



6 E. V. MeCollum, N. Simmonds and W. Petz, 

 Am. Jour. Physiol., 41, 361, 1916. 



1 From the Department of Comparative Pathol- 

 ogy, Washington Unirersity School of Medicine, 

 St. Louis and the Marine Biological Laboratory, 

 Woods Hole, Mass. 



