144 ON THE MOTIPIIOLOOICAL CONSTITUTION OF 



have already stated that the actinapophyseal elements of the 

 cranium are generally flattened or extended so as to abut 

 against one another, and against the other bones of the skull. 

 Thus the malar passes backwards in the fibrous membrane 

 which extends across the orbital opening, and which covers in 

 the temporal fossa. The final purpose of the malar is to afford 

 an abutment against the squamosal so as to strengthen the 

 flank of the mammalian head. The malar, therefore, in many 

 instances sends secondary processes upwards and inwards to 

 abut against other bones. "While I gladly avail myself of 

 Professor Owen's term " squamosal," and fully agree with him 

 as to the bone itself being a "radiating" element of the 

 cranium ; and while I more particularly assent to his very 

 beautiful determination of it as the "quadrate jugal" of the 

 bird, I must, nevertheless, contend for the much greater pro- 

 bability of its being a radiating element of the mandibular 

 than of the maxillary arch. Its intimate connection with the 

 quadrate bone in the development of the chick, and the dis- 

 union of it and the malar in certain Mammalia, appear to me 

 to indicate that they belong to distinct sclerotomes. 



The extended attachment from above downwards of the 

 inferior turbinal to the inner aspect of the maxillary of the 

 foetal ruminant, a form of attachment which is repeated in 

 the lachrymal process of the bone in the human subject, in- 

 dicates the primary actinapophyseal form of the bone. Its 

 elongation backwards on the inner aspect of the palate-bone, 

 and its prolongation forward to abut against the cartilaginous 

 actinapophysis of the vomerine hsemal arch, are secondary 

 processes in the development of the bone, and steps towards 

 the completion of that antero-posterior system of serially 

 homologous actinapophyses which constitute what may be 

 termed the inferior turbinal system. The inferior concha is 

 peculiar to the nasal fossa of the mammal. The sclerous 

 elements, which constitute its skeleton, in its most fully de- 



