1. The belief that the cessation of spinal growth and curve progression coincides with the completion of growth in the iliac apophyses has been confirmed in a review of material from 224 cases. This applies also to paralytic curves.

2. In a high number of cases this ossification centre showed an asymmetrical development on the two sides of the pelvis. The appearance of a separate posterior centre of ossification is also common, and probably represents an advanced stage in the growth of the iliac apophysis.

3. Menarche and the growth of the apophyses of the vertebral bodies almost always occurred in advance of the iliac apophyses. They should be regarded as early signs of maturation, not reliable in the prognosis of curve progression.

4. The growth of the iliac apophysis appeared to be unaffected by poliomyelitis.

1. The true deformity of kyphoscoliosis has received little attention. Twenty-one deformities of congenital origin, ten idiopathic, and two secondary to neurofibromatosis, are discussed. The diagnosis is established and usually first suspected by radiography.

2. The deformity was severe and progressive except in three cases; paraplegia occurred in five congenital cases.

3. Early correction and fusion are advocated in the hope of preventing paraplegia and because correction of the old-established deformity is difficult or impossible.

The evolution of an idiopathic scoliosis is determined by the site of the primary curve and by the age of onset. It is significant that thoracic primary curves are commonly severe and the early onset of this curve accentuates this feature. Early operation based on prognosis is practised but sufficient time has not yet elapsed to justify any conclusions.