Spina bifida and its associated skull defects.

Some degree of interest has recently been aroused in the question of the occurrence and incidence of spina bifida. Despite the efforts made by many theorists in the past, its mode of production still remains obscure; it is known' that fundamentally there is a defective formation of the mesodermal tissues surrounding the primitive neural plate, and that the process of chondrification and subsequent ossification of the early membranous spinal column may lead to the production of a minor fault such as spina bifida occulta, or to a major fault such as myelocele, meningocele, myelomeningocele, or syringocele, but the reasons why this defective development should be brought about are not known.