Although it has already been pointed out that the growth of skeleton-carpus varies in urban and in rural areas, this time a survey was made to disclose whether there is any noticeable difference between purely agricultural and non-agricultural families (merchant, civil servant, laborer, etc.) within one and the same rural community. 1. Ossification area: Babies from agricultural families were inferior in each age group. 2. In cases of babies under 6-months old whose nutrition index (Kaup) showed less than 14.9, those from agricultural families showed inferior ossification. 3. Delayed ablactation was observed more often in babies from agricultural families and such cases showed delayed ossification of skeleton-carpus. 4. The development of skeleton-carpus was inferior in babies whose mothers showed an advanced fatigue, i. e. premature senility: this phenomenon was more often observed in babies from agricultural families. 5. The mothers of babies from agricultural families more often showed a lower serum-protein value, and the babies were in the state of under-nutrition parallel thereto.
Lately, chromatography has come to be used for microestimation of matter. In this study, I divided conjugated fatty substance with the aid of magnesium oxide into cholinephosphatide and non-choline-phosphatide; next, by hydrolyzing the former, estimated the quantities of lecithin and sphingomyelin; then by hydrolyzing the latter, estimated that of cerebroside, and then by applying the Permutit method, estimated those of phosphatidylethanolamine and phosphatidyl-serine. While chromatography with magnesium oxide formerly required a considerable time for development, I resorted to mixing powdered glass (200 mesh) into the specimen in the 1: 2 weight ratio;thus working on the medium for such development, I succeeded in obtaining an efficient and perfect system for fractionation of fatty substance under which none of the fractions stuck to the adsorbent are lost.I also devised a system for causing the complete separation of non-choline-phosphatide from the adsorbent: first to dissolve MgO column in a liquid composed of equal quantities of 6N-HC1 and methanol, and then to extract fatty substance out of such solution with the use of ctloroform (CHC13). In this way, the five fractions of fatty substance i. e. lecithin, sphingomyelin, cerebrcside, phcsphatidyl-ethanolamine and phosphatidyl-serine are estimated in a series of continuous laboratory work.