THE BASICRANIAL RETE 



349 



seems that the rete holds the same relations to the surrounding parts in the adult as in 

 the foetus, but in consequence of the change in size and shape of those parts the form 

 and relative size of the rete has undergone considerable alteration. 



A B 



Fig. 8. A. Skull of a foetal Sei Whale, ventral view (from Schulte). B. Skull of an adult Sei Whale, 



ventral view. 

 Showing the difference in the arrangement of the parts of the basis cranii in the foetus and adult 

 a < MaxiUa h, Pterygoid bone 



b < Vomer l, Squamosal 



f ' Palat,ne j, Tympanic 



d > Frontal k, Exoccipital 



e, Internal pterygoid plate /, Basi-occipital 



/, External pterygoid plate m> Basi-sphenoid 



g, Hamular process 



The chief differences between the foetal and adult cranium (Fig. 8) are to be seen in 

 the short broad rostrum and the flat palate of the foetus, which contrast very markedly 

 with the prominent raised palatal ridge and the elongated pointed rostrum of the adult 

 Ihe rostrum is formed in the adult by the enormously lengthened maxillae embracing 



