Gyral development of the human brain

To determine the development of the convolutional pattern of the cerebral hemispheres, we have examined multiple gross photographs of 507 brains and serial sections of 207 brains from infants of 10 to 44 weeks' gestational age. The sequential developmental changes of the individual fissures, sulci, and gyri of the cerebral hemispheres throughout the gestational period are tabulated. Schematic drawings made from enlarged photographs show the major changes associated with each month of the second and third trimesters.