T. Goodkv and a. W. Wellings 
549 
5. Boy, aged 13, with inflammatory hypertrophy of the gum on the 
labial aspect of the maxillary incisors. Material was collected from 
beneath the enlarged gum festoons and was found to be very rich in 
amoebae. The hypertrophied tissue was removed, fixed in Bouin’s 
solution and embedded in paraffin. Serial sections were cut, stained 
by a variety of appropriate methods, and carefully examined for the 
presence of amoebae with a negative result. 
6. Girl, aged 16. Teeth in fairly good condition but the inter¬ 
dental gum papillae were somewhat enlarged and inflamed, due to the 
retention of food debris. Films made from the debris in the “trough” 
between the papilla and the tooth showed the presence of amoebae. 
7. Female, aged 21. Teeth well-kept and mucous membrane of 
the mouth generally healthy, but the margin of the gum around the 
upper right maxillary first molar was irritated by a small collection of 
salivary calculus, and had reached a stage of chronic inflammation. 
Films made from the material beneath the inflamed gum, and others 
made from healthy gum showed no amoebae. 
8. Male, aged 31. Mouth very well kept. Singularly free from 
dental caries. Case of true pyorrhoea alveolaris affecting chiefly the 
upper and lower incisor regions, the left lower molars, and to a slight 
extent the left maxillary canine (lingual aspect only) and premolars. 
In the infected areas the gum had a tense, glistening appearance and 
was of a deep bluish-red colour, deepened over the region of the pockets, 
so that one could distinguish by the colour of the gum the positions 
where the greatest amount of bone destruction had occurred. The 
interdental papillae were retracted; not removed by ulceration as one 
sees in some conditions, but drawn down tightly over the interdental 
bony septum, becoming more and more retracted, as more and more 
bone was destroyed. From the pockets, a fairly copious amount of pus 
could be expressed at almost any time; and on the roots of the teeth 
corresponding to the position of the retracted gum a deposit of hard 
black calculus was found, which in some places extended along the root 
for a short distance into the pocket. Films were made from the pus from 
around the upper incisors, but we did not detect the presence of the amoeba 
until we had examined upon the warm stage some of the material from 
the mandibular incisors. At no time were the amoebae very numerous, 
but the most favourable moment for them was in the first expressed bead 
of pus which would be contariiinated with a certain amount of debris. 
We cannot agree with the statement that the amoebae are most 
numerous at the bottom of a pyorrhoea pocket. Our experience proves 
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