6.58 



SKELETON. 



the ribs, then the cranial vertebrae, as verte- 

 brae, must have the ribs also. What other 

 cephalic structures, therefore, are there in the 



of cranial vertebrae, if these ribs be not the 

 maxillary arches ? * 



Now there happens in^zg. 481., between the 



head which may be said to 'stand as the ribs costiform maxilla (dd*) and thoracic ribs 



Fig. 481. 



The human cranio-facial and cervico-hyoid apparatus, 



Showing that the hyoid apparatus relates to the cervical vertebrae, and the facial apparatus 

 to the cranial vertebrae, just as the thoracic or costo-sternal apparatus relates to the dorsal 

 vertebrae. 



(q q q) which interrupts the idea of a con- 

 tinuous serial costal order ; at the same time 



vertebra," while compared to the osseous segment 

 taken from the bird's thorax, and which he terms 

 the " natural typical vertebra," does not correspond 

 quantitatively. In this ideal form I find the ribs 

 (pleurapophyses) but as mere rudiments, whilst in 

 the natural form I see that these ribs embrace tho- 

 racic space from the spine nearly to the sternum. 

 Again, in the ideal form the haemapophyses hang 

 appended to the vertebral centrum ; whereas in the 

 natural typical form they articulate with the distal 

 ends of the thoracic ribs. 



> tnat hiatus or gap in costal series 

 which is called the cervix, and it is this hiatus 



* In the " Homologies," the author names the 

 maxillae the " inverted arches " of the cranial ver- 

 tebrae. These inverted arches answer to the haema- 

 pophyses of the author's ideal typical vertebra, and 

 not to the pleurapophysial elements (the ribs^) of 

 that ideal form. Now I confess, for my own part, 

 that I do not see clearly why these maxillary arches 

 are referred to the former rather than to the latter 

 elements. There is evidently some mystery about 



the " Homo- 

 and for this 

 ideal typical 



