934 DR. A. HOPEWELL SSIITH AND DR. H. W. MARETT TIMS OX 



intermediate size, as this would have rendei^ed the precise 

 interpi'etation a. matter of less difficulty and of greater certainty. 

 Without going into details we will summarise as briefly as 

 possible the conditions found in the later stage. 



Upper .Taw. — Anteriorly is a small calcified tooth {A') occupying 

 a position similai- to the tooth found in the previous stage and is 

 undoubtedly the same tooth still persisting. It shows no signs of 

 being erupted, neither has it undergone any f urthei' development. 

 That it will ultimately become absorbed without attaining func- 

 tional activity seems to be certain. 



Behind this lies a large incisiform tooth already heavily 

 calcified. This tooth [B') is the largest of the anteiior sei-ies. 

 All traces of the tooth-band between A' and B' have become 

 lost, and several sections intervene between the disappearance 

 of A' and the commencement of the enamel organ of B' . Tlius 

 we are of the decided opinion that these are two morphologically 

 distinct teeth, a point to which i-efei'ence will be made later. 

 This conclusion is the same as that at wliich weaiTived in Stage T. 



C is still a small uncalcified tooth lying superficially, and 

 appears to have been pushed out of the sei'ial line towards the 

 outer aspect of the jaw. 



D' is very similai- to B' , but perhaps not quite so large. 

 Posteriorly to U is a small calcified tooth (£") of irregular shape 

 and situated close to the alveolar margin of the ja^v. This tooth 

 is obviously vestigial and will never become functionally active. 

 According to our identification this tooth is unrepresented in the 

 earlier stage. 



After an interval another large incisiform tootli is seen (7''"). 

 It is neither so large nor so heavily calcified as B' or D' . 



G' is a tooth of some size showing but traces of commencing 

 calcification. From its relation to the premaxillo-maxillaiy 

 suture we regard this tooth as the canine. It is a tooth in an 

 early stage of development which has appeai-ed since the age of 

 Stage I. There is a " concentric epithelial body" which is to be 

 regarded as the last trace of a vestigial predecessor. 



The first of the true maxillary teeth is elongated and of 

 premolariform type (//') without any indications of a predecessor 

 or successor. The third tooth (./') is like unto it but of much 

 larger size, extending through many more sections. 



Between these two calcified teeth is a ve7'y deeply placed tooth- 

 germ with a neck of remarkable length (/') (PI. XLVII. fig. 1). 

 There is no evidence of calcification. This is evidently the 

 second maxillary tooth which, crowded between the large calcified 

 first and third, has been forced into the abnormally deep situation, 

 besides being pushed from the linear series towards the palatal 

 side of the jaw. 



The fourth maxillary tooth {K) is large and in it calcification 

 is but just commencing. From the neck of the enamel organ 

 springs a marked labial downgrowth of the dental lamina, con- 

 nected with which is a " concentric epithelial body," the vestige 



