DEVELOPMENT OF VASCULAR DENTINE. 
43 
vascular formative pulps had withered or undergone some form of degeneration prior to 
the teeth coming into use. But in the Hake, at all events, such is not the case ; these 
movable teeth, capable of being, without injury, bent down to an angle of 60° with 
them normal position, are furnished with richly vascular pulps to the last. 
The blood-vessels (v) enter the pulp through a perforation in the ligament (see 
fig. 27) at a point which undergoes little or no change of position when the tooth is 
moved, and the pulps have no connection with the parts subjacent, except in the 
immediate neighbourhood of the ligaments ; and no blood-vessels enter it from below, 
as is usually the case in other tooth pulps. 
When the tooth is bent down the pulp is therefore carried with it, and is lifted up 
from the bone beneath it, but no strain is put upon any part of it. 
From the foregoing description it will be seen that the hinged teeth of the Hake 
have attained to an high degree of specialisation, and have in this matter of attach- 
ment attained to a close similarity with the teeth of Lophius, to which in structure 
they do not bear the smallest resemblance. Moreover the Lophius is an acanthopterous 
fish and the Hake one of the Gadidse (Physostomi), so that they are sufficiently remote 
from one another. And as it was remarkable that one member of the family of Gadidse 
should alone possess a structure believed to be very uncommon, I sought in other 
members of the family for any similar arrangement, and though I did not find it, I 
found what is of more interest, namely, what may be regarded as transitional steps 
towards its attainment. 
Professor Owen (‘Odontography/ p. 162) says, “All the teeth are less firmly 
attached to the bones in the Gadoids than in other osseous fish with laniariform 
teeth. In the Cod-fish the gelatinous conical pulp after having formed the body 
of the tooth, is continued in an uncalcified state, but condensed into ligamentous 
firmness, from the base of the tooth to the alveolar margin of the jaw ; ossification 
then proceeds from the jaw along the ligaments towards the base of the tooth, 
which, however, rarely becomes anchylosed to the ossified ligaments. The teeth 
therefore of the Cod are generally detached in macerating the head, and the broad 
alveolar margin of the dentigerous bones is then covered by the ossified dental 
ligaments in the form of truncated cylinders of various sizes, the largest being the most 
external in the intermaxillary and the reverse in the premandibular bones.” 
It is thus well known that the teeth of the common Cod are not fir ml y anchylosed to 
the bone, so that they are often lost when the skull is macerated, being held in place 
by ligamentous fibres only. But it is not generally known, nor had I myself any 
suspicion until after examining the teeth of the Hake, that they (the teeth of the 
Cod) are normally possessed of a slight degree of mobility, and that they have 
sufficient resiliency to at once resume the upright position. Like the teeth of the 
Hake, they can be bent inwards towards the mouth, though only a very little way, 
and they cannot be bent outwards at all. 
This is effected by the arrangement of bony support and ligament shown in fig. 25 ; 
G 2 
