
MY WORK AND BACTERIOLOGY 303 
gators have testified to much the same mode of 
origin. No single factor of unwholesomeness at 
Princetown could be pointed to as having been 
associated with the observed incidence of the 
disease ; but the clue to an explanation was afforded 
by a general prevalence of much and marked sore- 
throat in the district, and by the tender age of the 
children first attacked. Dr Sweeting says :— 
“There seems, therefore, reason to suspect that 
diphtheria was evolved amongst young children 
from previous minor sore-throat in the village, and 
developed itself in the infants’ class at the school ; 
that the disease thus set up was kept going by 
assemblage of susceptible children at school, and 
by the further reinforcement of sore-throat when 
the school was closed ; and [the disease] was spread 
by infection from person to person at school and 
elsewhere.” 
Further, in a recent able communication by Dr 
Hubert Biss on the ‘ Borderlands of Diphtheria 
and Scarlet Fever,” written after a large experience 
in a fever hospital, we find him saying,! ‘“‘ The 
nuances between these conditions—scarlet fever, 
diphtheria, and tonsillitis—are so gentle that each 
shades off into the other not at one but at many 
points.” And quite lately he has reiterated his 
view that the two diseases, scarlet fever and 
diphtheria, are to some extent interchangeable. 
He says,’ “ But there was no question of theory. 
The metamorphosis actually took place. Scarlet 
1 The Lancet, 1903, ii. p. 1296. 
2 Prit. Med. Journ., 1906, ii. p. 895. 
