Abstract
1. Cephalin was found to constitute a principal part of total lipids in the central nervous tisues.
2. The changes in the amounts of lipids and total nitrogen in the course of fetal growth were very remarkable in nervous tissues, except that lipids increased and total nitrogen decreased considerably in cere-brum, medulla oblongata and spinal cord during fetal growth.
3. The increase in lipids occurred most conspicuously in cere-brum and less remarkably in medulla oblongata and spinal cord. 4. The lecithin content increased considerably with the fetal growth in medulla oblongata and spinal cord, but in cerebellum it re-mained almost unchanged; whereas sphingomyelin content in cerebel-lum changed quite inversely in quantity.
5. The changes in cholesterol and cerebrosides in amount were most distinct in the last 2-3 months, but for in cerebellum.
6. The ratio of total phospholipids to cholesterol showed a tenden-cy to decline in all the four tissues, but noticeably in cerebrum in the 2nd-4th months; as to that of cephalins to cholesterol, the same changes were also confirmable.
7. The ratio of total phospholipids to cerebroside showed the tendency to decrease in all the four tissues, while that of cerebrosides to sphingomyelin inclined to increase except for in cerebellum.
