590 VI. OCCURRENCE OF LIPIDS IN THE ANIMAL 



saturated acids than does the variety native to India and the East Indies 

 (Celastrus paniculata) . 318 According to Hilditch, 116 a similar but less 

 striking variation in unsaturation of seed oils as related to environmental 

 temperatures can be noted for the several species of beech (Fagaceae), of 

 argemone and poppy (Papaveraceae), of sesame (Pedaliaceae), of safflower 

 (Compositae) , of grape ( Vitaceae) , and even of the pea, or pulse (Legumino- 

 sae). Painter and associates 319-321 have ascribed the wide variations in the 

 iodine number of linseed oils partly to the temperatures occurring during 

 ripening, as well as to the conditions of moisture. 



On the other hand, there is ample evidence that the most highly un- 

 saturated fats are to be found in seed oils from tropical plants. In a plant 

 family such as the Rosaceae, the oils from the rose-hip, or wildbriar (Rosa 

 canina) 322 and blackberry seed (Rubus caesius) , 323 which are from temperate 

 zones, are much more saturated than are those from such tropical species as 

 oiticica (Licania rigida), 32i "fungu" or "behurada" (Parinarium campestre) 

 from Surinam, and "po-yoak" (Parinarium sherbroense) from Sierra 

 Leone. 325326 In the latter cases, triethenoid and tetraethenoid acids are to 

 be found. A similar pattern obtains in the different members of the 

 Euphorbiaceae. Thus, seed oil from the caper spurge (Euphorbia lalhy- 

 rus), 327 which is a plant from the temperate zone, does not contain the 

 highly unsaturated fatty acids (such as linolenic) present in the tropical 

 Brazilian (Para) and Nigerian rubberseed (Hevea brasiliensis), 313 ' 32 *- 329 

 or those, such as elaeostearie, in the tung oils, Aleurites cor data 

 (Chinese varnish tree), 330 A. fordi, and A. montana ("mu oil" or china- 

 wood), 331,332 and in the West African gingerbread plum, or "neou" (Par- 

 inarium macrophyllum) which is used as a substitute for tung oil. 332 



313 B. G. Gunde and T. P. Hilditch, J. Chem. Soc., 1938, 1980-1985. 



319 E. P. Painter, Oil & Soap, 21, 343-346 (1944). 



320 E. P. Painter and L. L. Nesbitt, Ind. Eng. Chem., Anal. Ed., 15, 123-128 (1943). 



321 E. P. Painter and L. L. Nesbitt, Oil & Soap, 20, 208-211 (1943). 



322 P. Vasterling, Arch. Pharm., 260, 27-44 (1922). 



323 R. Krzizan, Chem. Rev. Felt- u. Harz.-Ind., 15, 7-9, 29-30 (1908); Chem. Abst., 2, 

 1352 (1908); cited by T. P. Hilditck The Chemical Constitution of Natural Fats, 2nd ed., 

 Wiley, New York, 1947, p. 166. 



324 J. Van Loon and A. Steger, Chem. Umschau Gebiete Fette, Die, Wachse, u. Harze, 37, 

 337-340 (1930). 



325 A. Steger and J. Van Loon, Rec. trav. chim., 57, 620-628 (1938). 



326 A. Steger and J. Van Loon, Fette u. Seifen, 49, 769-770 (1942); Chem. Abst., 38, 

 1655 (1944). 



327 B. Tyutyunnikov, A. Sobel, and V. Erschova, Maslobolno-Zhirove Delo., 11, 132- 

 133 (1935); Chem. Abst., 29, 8375-8376 (1935). 



328 F. D. Gunstone and T. P. Hilditch, J. Soc. Chem. Ind., 65, 8-13 (1946). 



329 G. S. Jamieson and W. F. Baughman, Oil & Fat Ind., 7, 419-421, 437 (1930). 



330 R. S. McKinney and G. S. Jamieson, Oil & Soap, 14, 2-3 (1937). 



331 R. S. McKinney and G. S. Jamieson, Oil & Soap, 12, 92-93 (1935); 15, 30-32 

 (1938). 



332 T. P. Hilditch and J. P. Riley, /. Soc, Chem. Ind., 65, 74-81 (1946). 



