Mat 20, 1921] 



SCIENCE 



487 



anticipated, so that two large volumes tave 

 been necessary to describe them. These two 

 volumes contain 1,846 pages and 1,783 figures. 

 In these volumes the treatment used in the 

 others has been followed. 



Chemists and crystallographers, the world 

 over, are greatly indebted to Professor Groth 

 for this most important reference work, which 

 is a critical survey of all the crystallized mate- 

 rial described thus far. As is generally 

 known. Professor Groth has devoted his life 

 to problems in chemical crystallography. He 

 was the founder of and for many years the 

 editor of the Zeitschrift fuer Krystallographie 

 und Mineralogie. Hence, he was peculiarly 

 fitted to undertake this very difficult and time- 

 consuming task. Edward H. Kraus 



minebalogical laboratory, 

 TJniversitt of Michigan 



SPECIAL ARTICLES 



THE CHANGE IN THE FAT OF PEANUT-FED 

 RABBITS 



In the course of our investigation of the 

 soft pork of i)eanut-fed hogs it occurred to 

 me that if an animal in starving used its 

 liquid fat first, this would make it pos- 

 sible to overcome the softness of the pork on 

 peanut-fed hogs. If the animal used the 

 liquid fat first in starving it would be reason- 

 able to suppose that if both liquid and solid 

 fat were fed at the same time he would use 

 a greater proportion of the liquid fat to meet 

 the energy requirements of his body. Then 

 it would be iwssible to attack the soft pork 

 problem in two ways. One would be to feed 

 peanuts alone for forty or fifty days then 

 starve the hog for some eight or ten days so 

 as to remove the liquid fat as much as pos- 

 sible, and afterwards finish the feeding with 

 other feeds. The other way would be to feed 

 the peanuts not alone for forty or fifty days 

 as is the custom but to feed them with some 

 feed that would produce solid fat and in this 

 way the animal would use a greater percent- 

 age of the soft fat that was fed than he would 

 otherwise. We got some results this past 

 spring which indicated that it is much better 

 to feed the hogs peanuts with other feeds for 



seventy days than it is to feed for forty or 

 fifty days with peanuts alone, then to finish 

 with other feeds. 



To determine whether an animal in starv- 

 ing uses the liquid fat more rapidly than it 

 does the solid fat, rabbits were fed on peanuts 

 and alfalfa for six weeks. One of the rabbits 

 was killed at the end of the feeding period 

 and the others were killed after starving 

 three, five and seven days. The iodine num- 

 bers of the kidney fat and the back fat were 

 determined. Two series of rabbits were 

 treated in this way but the results of the last 

 series only will be given. 



Iodine Number Iodine Number of 



Rabbit No. ot Back Pat Kidney Fat 



1 96.23 98.00 



2 78.34 97.92 



3 70.98 95.83 



4 66.22 92.36 



The per cent, of the livers extracted by 

 ether, were rabbit 1, 8.15, raJbbit 2, 17.04 

 rabbit 3, 19.18, rabbit 4, 20.09. It was ex- 

 pected that the ether extract of the livers 

 would increase in starvation and it was 

 thought that the iodine number of this ex- 

 tract would increase but in this last we were 

 disappointed as the iodine number was prac- 

 tically constant, showing the values from 98 

 to 104. 



Our results indicate that the liquid fat 

 of an animal during starvation is used more 

 rapidly than the solid fat, that the liquid 

 fat of the back or subcutaneous fat is used 

 more rapidly than that of the kidney. It is 

 our intention to repeat this work, beginning 

 in about a month, using pigs instead of 

 rabbits. 



S. T. DOWELL 



Oklahoma Agricultural 

 Experiment Station, 

 Stillwater 



THE AMERICAN SOCIETY OF MAM- 

 MALO GISTS 



The third annual meeting of the American 

 Society of Mammalogists was held in the 

 United States ISTational Museum, "Washington, 

 D. C, May 2-4, 1921. Officers elected for the 



