JOUENAL 



OF THE 



ROYAL MICROSCOPICAL SOCIETY. 



DECEMBER, 1916. 



TRANSACTIONS OF THE SOCIETY. 



XV. — On Certain Parasites of the Mouth in Cases of Fyorrhcea. 

 [Preliminary Communication.} 



By Helen Pixell Goodrich, D.Sc, and M. Moseley. 



{Read October 18, 1916). 

 Plates XII-XVII. 



Pyorehcea is such a widely distributed disease of the gums that 

 it is hardly necessary to say much by way of introduction. To 

 make sure, however, that the normal anatomical relations of the 

 parts concerned are understood, it will be well to make brief 

 reference to the microphotograph of a section taken transversely 

 across the jaw of a puppy (figs. 2, 3). 



For obvious reasons it is difficult to obtain human material 

 suitably fixed for cytological purposes. Most of our series of 



EXPLANATION OF PLATE XIL 



Pig. 1. — Diagram of a section transversely across a Mammalian jaw from the 

 labial to the lingual side, through a single root of a tooth. 



,, 2. — Microphotograph of a section through the tooth of a puppy, in the same 

 direction as above, x 7. 



„ 3. — Microphotograph of the region round the gingival space of the section 

 shown in fig. 2. x 35. 



„ 4. — Microphotograph of a similar portion of a section through the tooth 

 and gum of a person with fairly advanced pyorrhoea, showing the 

 gingival space still free from organisms. A good deal of recession 

 has taken place ; the crusta petrosa may be seen to extend nearly to 

 the top of the figure, showing where the gum was originally attached. 

 Note that the lesion is at the top of the gum, where clumps of 

 Leptothrix and pus-cells are scattered (the tartar ridge which was 

 attached to the tooth just above here became detached during prepara- 

 tion of the section). The epithelium is much infiltrated with pus- 

 cells. X 50. 



Dec. 20th, W16 2 N 



