JOURNAL 



OF THE 



KOYAL MICROSCOPICAL SOCIETY. 



APRIL, 1917. 



TRANSACTIONS OF THE SOCIETY. 



II. — The Parasitology of Pyorrhoea alveolaris. 

 By Aubrey H. Drew, D.Sc, 



Bacteriologist to the Eoyal Institute of Public Health and Lecturer on 

 Bacteriology, Royal Dental Hospital, London, 



AND 



Una D. Griffin, M.B., 



Assistant Bacteriologist, Guy's Hospital. 



(Read February 21, 1917.) 



Plates XIV to XVII and 1 Text-Fig. 



The investigations forming the subject-matter of this paper were 

 carried out in the Bacteriological Laboratories of the Royal Dental 

 Hospital and the Royal Institute of Public Health. The work 

 was originally commenced in collaboration with Dr. W. J. Penfold, 

 of the Lister Institute, and it was our intention to ultimately 

 publish a joint paper. Owing to Dr. Penfold having left this 

 country for Australia he was unable to continue the work, and it 



EXPLANATION OP PLATE XIV. 



A typical dark-ground preparation from a bad case of pyorrhoea. 



Fig. 1. — New species of flagellate. 



,, 2. — Trypanosome-like form. 



,, 3. — Spirochxta buccalis. 



,, 4. — Treponema vincenti [Spirochaeta vincenti). 



„ 5. — T. macrodentium. 



„ 6. — T. microdentium. 



,, 7. — Spirochaeta refringens. 



,, 8. — Various bacteria. 



,, 9. — Leptothrix filaments, coarse and slender. 



April 18th, 1917 o 



