DEVELOPMENT OF THE FACE. 7 



(2) The lateral mass of the ethmoid, at first merely a plate 

 of cartilage ; the superior and middle turbinate processes are 

 developed from the plate (Fig. 7) ; ossific centres appear in the 

 cartilage of the lateral mass and turbinate processes during the 

 fourth month of foetal life ; 



(3) The inferior turbinate bone (Fig. 7) (maxilld-turbinal). 

 The body of the superior maxilla is developed on its outer side 

 in the maxillary process (Fig. 7) ; 



sup. turb. 

 lot. nas. proa 



mid. turb. 

 inf. turb. 



-frontal, 

 orbit pi. front. 



septum 



nas. proa.) 



max. (max. pmc.) 



sac 



vomer palate (max. proc.) 



Fig. 7. — Coronal section of the skull of a 7th month human foetus to show the 

 cartilages of the Lateral and Mesial Nasal Processes and the bones formed 

 round them. 



(4) The lateral and part of the alar cartilages of the nose ; 



(5) In the membrane over the cartilage, between the ethmoid 

 behind and the cartilages of the nares in front, are developed the 

 lachrymal and nasal bones, and the ascending process of the 

 superior maxilla. The cartilage beneath these bones disappears 

 after birth (Fig. 6). 



Arteries and Nerves of the Nasal Processes. — 1. Mesial 

 Nasal Process. The chief artery and nerve of this process are 

 the naso-palatine, but branches also come from the nasal nerve 

 and its accompanying artery, the anterior ethmoidal. 



2. Lateral Nasal Process. The lateral nasal nerves are derived 

 from Meckel's ganglion and the descending palatine nerve. Vessels 



