ENAMEL 93 



2. That in the Sparidse a tube system from the dentine 

 is fully developed in some species, the outer and inner 

 systems of tubes existing together. 



3. That a progressive calcification of the larger part of 

 the enamel takes place in its interior in teeth that have not 

 yet come into use, and that this process is continued by the 

 agency of the tubes and their contents. 



In the group Scarus of the Labridse (Wrasses) there is 

 a still more complete penetration by tubes from without 

 than in Sargus. In the specimens examined the tubes took 



FIG. 47. Tubular enamel of Pseudoscarus. d. Dentine ; 

 e. enamel. ( x 50.) 



the stain freely, entering the enamel in parallel straight 

 lines as in Sargus, but more intricately crossed and inter- 

 woven in the deeper parts than in any of the Sparidae. 

 The enamel of the pharyngeal teeth of Scarus forms a 

 very thick investment to the tooth, and the tubes, after 

 passing in for about one-third of its width, cross one 

 another in all directions and course along the dentine 

 margin parallel to its surface, but appear to have no connexion 

 with it, at all events in the species of Scarus examined. 

 Fig. 47 shows the great abundance of these tubes and the 

 complicated pattern which they form. A very remarkable 

 peculiarity of these teeth of Scarus is the very small amount 

 of dentine in comparison with the bulk of the enamel seen 

 in most specimens, both of the pharyngeal teeth and those 



