The Etiology of any condition is always important because upon its correct conception all rational treatment must be based. Unfortunately our knowledge of the causating factors of cleft palate are extremely meagre. We know that it is due to a non-fusion of the embronic internal nasal, palatal, and occasionally also the ethmo-vomerine plates.

Maternal impressions are popularly cited as a cause of the frequently associated condition of hare lip. In one case a mother was not surprised in the least at the presence of the hare lip—in fact she had expected it—for during the fourth month of pregnancy she had received a severe fright from seeing a boy with a badly-cut lip. The boy was found and examined shewed a scar in a similar position to the infants' cleft. Absolutely convincing, popularly. Unfortunately, however, for popular pathology the embryonic plates concerned unite at the eighth to tenth week.

Acute illness on the part of the mother about latter time may account for the condition. Atavism certainly will not; for although many progenitors of man have cleft lips, none have cleft palates.

The embronic processes may be said not to unite either because of the arrest of development or because the width of the space to be bridged is too great for :the inherent tendency to growth" of the parts to overcome.

As a matter of fact I think both these causes operate either combined or separately—sometimes one, sometimes the other. Regarded thus, we can recognise two chief clinical varieties of complete congenital cleft palate. (1) Those in which the cleft is wide, maxillae wide and tissue of soft palate normal in amount. (2) Those in which the cleft is of medium width, maxillae narrow and tissue scanty.

Upon the recognition of these varieties depends I believe the selection of the correct form of treatment, for cleft palate is essentially a condition where is no "best" and should be no "favourite" of treatment.