December 8, 1922] 



SCIENCE 



651 



our ration. Such a diet is 'furnished by rolled 

 oats (40), gelaltiu (10), oasein (5), desiti-in 

 (40.3), butterfait (1), amd salts (3.7) (MeCol- 

 lum). It is perhaps also pertiuenit to point 

 out thait we have delteeted lun. invariable sign of 

 inadequacy in the A faeifcor of igreaiter delicacy 

 than 'those hithento employed and may thus 

 recognize suoh inadequacy long before growth 

 impairment, for instance. The sign is con- 

 stituted by a highly cbaraateiisitic aberration 

 of the oestrous cycle. And we have been able 

 to demonstrate the pei-sis!tence of fertility with 

 a wheat-milk rabkm (Sherman) even in the 

 absence of butiterfat and when the A deficiency 

 is heralded by the oontinuous exhibition of the 

 new sign. The beneficial effect of a very high 

 percentage of butterfat,' consequently, seems 

 pi-efera'bly explained by its possession of a. 

 definite though low quota of the fertility con- 

 ferring substance. Furthermore, a sample of 

 cod liver oil tested by ns and proven to possess 

 a much superior A content to butterfat is far 

 less efficacious than butter in curing or pre- 

 venting the impairment of the reproductive 

 function. 



The beneficial didtary fadtor can not be iden- 

 tical with the antiscorbutic vitamine C, for 

 curative effects have 'been secured when ground 

 whole wheait was added to our purified ration, 

 and the cereals are, of course, noltably deflcienit 

 in C. Moreover, althiough some favorable in- 

 fiuenee on growth has (been noited, it has been 

 impossible for us to -secure viith orange juice 

 the fertility effecits so evident with lettuce. 



Lastly, we may refer to the suggestions 

 either implied or expressed in the publications 

 of some investigators (Osborne and Mendel, 

 Kennedy and Palmer) that yeast contains some 

 toxic substance inimical to the organs of gen- 

 eration and hence causing sterility or that it 

 simply does not contain enough of the water 

 soluble vitamine B. The curative foods could 

 hardly be assumed to detoxify. Nor do we 

 believe our animals suffered from, lack of B, 

 for growth was excellent; and as miuch as 25 

 per cent, by weight of yeast (which must have 

 given a great surplus of B) did not change the 

 result. Fertility, when wheat geiTU is used as 

 a source for B, results not fix)m more B but be- 

 cause wheat germ is also rich in X. 



We have undertaken a series of experiments 

 designed to trace further in natural foods the 

 disifribution of tihe substance thus shown to be 

 indispensable for the production of healthy 

 j-oung. 



Herbert M. Evans 

 K. Scott Bishop 



THE RECENT SCIENTIFIC WORK OF 

 ROBERT WHEELER WILLSON 



It must be of iuteresit ito the many friends 

 and former studenits of Professor Robert W. 

 Willson to know that the last months of his. 

 life were actively occupied in the successful 

 solution of certain scientific problems. 



Professor Willson died 'alt his home in Cam- 

 bridge, November 1, 1922, in the seventietL 

 year of his age. He was a graduate of Har- 

 vard College in the class of 1873, and took his- 

 Ph.D. at Wiirzburg a few years laJter, after 

 specializing in physics, a subject which, in co-n- 

 junetion with his astronomical experience, gave 

 juisit the right equipment for his solution of 

 aerial navigation problems at a much later- 

 dalte. 



The main facts of his professional career are 

 available in the biographical 'reference books, 

 while oithers can speak more fully than I of 

 his devotion to ,tlhe building up of a depart- 

 ment of astronomy in Hai'vard College. Fol- 

 lowing his retirement as professor emeritus in 

 1919, he devdted an increasing amount of time 

 to his own work in Cambridge along the line 

 of air navigation instruments, 'and this later 

 work is not perhaps so well known. 



His development of the air-eraft sextant was- 

 a notable achievement successfully demon- 

 strated 'during the war, and widely adopted 

 since. Anti-aircraft 'defense, trans- Atlantic 

 flight, and ground speed inddoat'Ors were only 

 a few of the subjects Avhich claimed his keen- 

 eslt attention and m which definite progress - 

 had been made. He was fully awai-e of all the 

 trying obstacles which must be met in the de- 

 velopment of instruments for praotioal air- 

 plane use, and noit only had a 'Sound, scientific 

 solution in readiness for each case, bult was. 

 equally 'alert to suggest the anost eeonomicaL 

 method of construction. 



