228 



SCIENCE 



[N. S. Vol. XXXVII. No. 945 



history. For comparison the following intra- 

 racial (inter-individual) coeiScients of varia- 

 tion for fecundity in other forms are tabled: 



Constants of Variation in Fertility and Fecundity 

 in Various Animals 



It is plain that the individual variability in 

 " size of litter " shovpn by this ewe is of the 

 same general order of magnitude as that 

 found in other organisms for fecundity char- 

 acters. E.4YM0ND Pearl 



THE INDUCTION OF NONASTRINGENCY IN PERSIM- 

 MONS AT SUPRANORMAL PRESSURES 

 OF CARBON DIOXIDE 



In a previous issue of this periodical/ I re- 

 ported the results of some experiments to de- 

 termine the relation of different pressures of 

 carbon dioxide to the rate at which persim- 

 mons are rendered non-astringent by means of 

 that gas. Two varieties were used in those 

 experiments, Taher 129 and HyaJcume, as 

 these are understood at the Alabama Experi- 

 ment Station. I had already found that 



^ Bionetriha, Vol. VI., pp. 433-436, 1909. 



^ BiometriTca, Vol. V., pp. 442, 1907. 



' Fecundity in this ease means the fraction which 

 the actual number of offspring arising from a 

 given number of coverings is of the possible num- 

 ber of offspring under the circumstances. 



^ BiometriJca, Vol. I., pp. 289-292, 1902. Actu- 

 ally only the moments of this fecundity curve are 

 given at the place cited. From the moments we 

 have calculated the coefficient of variation. 



° Biometrilca, Vol. V., p. 251, 1905. 



"U. S. Dept. Agr., Bur. Anim. Ind., Bull. 110, 

 Part I., pp. 1-80, 1909. 



^ Lloyd, F. E., "Carbon Dioxide at High Pres- 

 sure and the Artificial Eipening of Persimmons," 

 Science, N. S., 34: 924-928, December 29, 1911. 



under normal pressure of pure and of approx- 

 imately pure carbon dioxide" these varieties 

 occupied from six to eight days in losing 

 astringency, the HyaJcume being the slower to 

 respond to treatment. Under a pressure of 15 

 pounds of pure carbon dioxide, the period was 

 found to be reduced to less than 46 hours. To 

 be more explicit, 24 hours was found to be in- 

 sufficient for either variety, while at the end 

 of 46 hours all astringency had totally disap- 

 peared. The minimum period required at this 

 pressure was not determined at the time for 

 lack of material. It was, however, quite evi- 

 dent that the time necessary to render these 

 varieties non-astringent at normal pressure of 

 carbon dioxide can be reduced to less than one 

 fourth at 15 pounds. It then remained until 

 the season just closed to determine these rela- 

 tions more accurately and with reference also 

 to still higher pressures. It is upon this work 

 that I desire to submit at this time a prelim- 

 inary report. 



Meanwhile the results of experiments made 

 by Dr. PI. C. Gore" on the effect of carbon di- 

 oxide at normal pressure have appeared. The 

 varieties which he studied include Taher 23 

 and IIyahu')ne, so that his results are dis- 

 tinctly pertinent in the present connection. 

 Gore used a metal receiver especially designed 

 by him to meet practical requirements, and, 

 as indicated by his controls, is doubtless as 

 elHcient for exact experimentation as a glass 

 receiver. The experiments with HyaTcume 

 were done at Macclenny, Fla., so that the fruits 

 of this variety were not subject to the exi- 

 gencies of transportation. As to these condi- 

 tions, therefore. Gore's experiments may be 

 regarded as directly comparable to my own, 

 which also were done on the ground in metal 

 glass and wooden receivers. Gore's Taher 23 

 fruits were processed in Washington. As to 

 the numbers of fruits used in Gore's experi- 

 ments, only three of HyaTcume were available, 



' The protocols of these and the remaining ex- 

 periments will be published elsewhere in full. 



' Gore, H. C, ' ' Large Scale Experiments on the 

 Processing of Japanese Persimmons, with notes on 

 The Preparation of Dried Persimmons," U. S. 

 Dept. of Agri., Bur. Chem., Bull. 155, May 10, 

 1912. 



