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is fair to presume, however, that the single animal is to a certain extent 

 typical, and therefore represents to that extent racial characteristics. 



LECITHIN. 



The determination of lecithin in meat products is accomplished, as 

 has been already described, by an indirect method ; namely, by the 

 extraction of the lecithin with a mixture of ether and alcohol and the 

 determination of the phosphorus in the extract. From the quantity 

 of phosphorus determined the percentage of lecithin is calculated by 

 factors based upon the percentage composition of the lecithin itself. 

 The data given for the lecithin should be accepted with certain restric- 

 tions, based upon the difficulty of applying the analytical processes. 

 In the extraction of the fat by ether a certain quantity of the lecithin 

 is removed. If, now, the residual lecithin be determined in the undis- 

 solved matters, namely, the dry flesh, the quantity obtained does not 

 represent fully the whole amount originally present, but rather the 

 quantity present in the muscular tissue itself. Therefore, in case of 

 the meats especially, the data must be accepted as showing the quan- 

 tity of lecithin in the fleshy portions of the meat, and not the quantity 

 originally present in the fleshy portions plus the fat. In the case of 

 the marrow and spinal cord, another difficulty presents itself; namely, 

 that there was not a sufficient quantity of the material on which to 

 perform the whole of the analytical operations. Inasmuch as the ether 

 extract comprises a large percentage of the whole weight of these 

 bodies, it is evident that the determination of the lecithin in this 

 extract represents approximately the quantity present in the original 

 material. On account of the paucity of this material, therefore, the 

 lecithin was determined in these cases in the ether extract alone. If, 

 however, the quantity be desired for the whole material, it is evident 

 that the data given are not sufficiently large. 



PHYSIOLOGICAL IMPORTANCE. 



From a physiological point of view lecithin is of prime importance. 

 It is quite certain that this body forms the transition state between the 

 phosphates of the animal body on the one hand and the mineral phos- 

 phates absorbed by plants on the other. In the growth of plants the 

 mineral pjiosphates are converted, to a certain extent, into lecithin, 

 which is found especially in the seeds, those of an oily nature predomi- 

 nating in lecithin bodies. In the consumption of vegetable foods by 

 animals the lecithin doubtless plays an important function in being 

 transformed again into a mineral compound, namely, the tricalcium 

 phosphate of the bones. Other portions of the lecithin become assimi- 

 lated in the tissues of the body, and especially in the brain, spinal 

 cord, and marrow. In the consumption of animal products by other 

 animals lecithin again plays an important role in nutrition, forming on 

 the one hand the bony structure of the animal eating the flesh, and on 



