The distribution of pneumatisation in the skeleton of the adult domestic fowl.

Abstract

In the skull of eight adult White Leghorn birds examined grossly and histologically, pneumatization occurred regularly throughout the neurocranium and in the quadrate and variably in the mandible, but seemed to be absent in the facial skeleton. On examination of the entire skeleton of 51 adult Golden Comet birds the previous findings were confirmed with the additional information that pneumatization in the pterygoid was variable. Variation in the extent of skull pneumatization was less than in the postcranial skeleton, where only cervical vertebrae 5-9 were regularly pneumatized. The humerus and coracoid were variably pneumatized, often unilaterally. The os coxae and sternum had a very low rate of pneumatization.