From my observations I am inclined towards the
following views: -
(1) That the size of the nasal spine depends to a large extent on the Facial Prognathism.
Where the facial prognathism is great a smaller
spine is present because the whole anterior part
of the maxilla is on a plane anterior to the
nacion and with a fixed septal length a smaller
support in the way of a spine is necessary than
in crania where the Facial Prognathism is small,
as in Europeans.
(2) To a less extent with a given Facial Prognathism
the spine will be smaller in a skull with smaller
nasal Prognathism than in one with a greater.Nasal
(3) Alveolar prognathism when very marked is also
a factor in determining the size of the nasal
spine, especially when accompanied by marked
flattening of the angle between the ant. post
plane of the hard palate and the plane of the
posterior surface of the Incisor alveolar area.
This is well brought out in Anthropoid skulls, where
the spine is absent and a groove for the lower surface^of the septem is present instead.
It must be noted, however, that the facial and
alveolar prognathism go hand in hand, so to speak,
because other conditions being equal, the more
prominent the prosthign the greater will be the facial
Slight Alveolar prognathism unassociated with increased p facial prognathism would tend to produce
a large rather than a small spine to support the
(4) Line (1) is well marked in Australian skulls and
I think this is in part due to the fact that the
ata of the nose are attached face on
lateral to that of the bony later uá11 and are
flattened. They are attached to line (1) which
attachment tends to prevent "splaying out" of alae.
In Europeans the ala4 nasi are nót flattened and
are not attached to the face in a plane lateral to
that of the bony lateral nasal margin to any marked
extent, and therefore do not require to have their
lateral attachment drawn towards the mid. line.
This may have something to do with the feeble marking
and Inferior rather than medial inclination of line
I was unable to determine the importance of the
size and inclination of ti-e Incisor teeth as a
factor in determining the configuration of the
Inferior nasal region, as set forth by Lightoller
The fact, as will be seen in many of the skulls I
examined, e.t. X X6 XX1X G24) that alveolar prognathism per se is not a potent factor in the deveippment of the nasal spine, is rather against the idea
of the pressure having any great influence.
XX1X. B7. D9. 7. E34. 28. 20. 17. 15. 9.5. F 7. G24)
and ßi.6. and numerous others have a greater
alveolar prognathism than is typical of their group
and yet have very large spines.
On the whole, I am more inclined to agree with
Klaatsch that the development of a large spine is
due to the departure of the human species from the
snout like nose of lower forms where the nose and
mouth are very close together.