PA TIIOdENESIS 4-15 
fail to penetrate the skin and infect the animal. This cutaneous test 
is of great diagnostic importance. 
McCoy and Chapin^ have described a disease superficially resem- 
bling plague in its pathological anatomy caused by B. tulara^nse. 
The disease is readily transmitted to guinea-pigs, rabbits and mice, 
less readily to rats. Wherry and Lamb- have isolated this organism 
from an epizootic among wild rabbits and from a human case present- 
ing corneal ulcerations and lymphadenitis.^ 
Man.— Vlague occurs in man characteristically as one of four clinical 
types : 
1. The mild, or ambulatory, type in which the febrile reaction is very 
mild and the glandular enlargement slight. Slight tenderness of the 
infected glands may or may not be detectable. 
2. The bubonic type, characterized by prodromal symptoms, which 
are generalized, malaise, some gastro-intestinal disturbance, and a grad- 
ually increasing sense of pain at the future site of the bubo. This is 
followed by the sudden onset, with rapidly rising fever, rapid pulse, 
and marked prostration, both mental and physical. Buboes appear 
in the groin, axilla or neck, in the order of occurrence mentioned. They 
soon become very tense, and may either suppurate or gradually dis- 
appear. 
3. The septicemic type —in which the onset is very abrupt, the fever 
very high, rapidly developing prostration, and frequently delirium. 
Punctiform hemorrhages (hemorrhagic septicemia) occur in the skin 
and on mucous membranes, and death usually ensues. It may occur 
within the first twenty-four hours, or within four days. If the patient 
survives five days, the chances for recovery are greatly enhanced. 
4. The pneumonic type, usually the most fatal of all. The symp- 
toms are usually those of a rapidly developing primary pneumonia. 
Death occurs in from forty-eight hours to six days. Generally speak- 
ing, the incubation period of plague is from two to ten days; the average 
is about three days. 
The atria of infection are chiefly the skin and the respiratory tract, 
giving rise to two general types of the disease, glandular and pneumonic 
plague. The organism may, however, enter the tissues through the 
tonsils, conjunctivae and the mucosa of the mouth, nose or naso- 
pharynx.'' Rarely a localized cutaneous lesion, plague carbuncle, is 
met with where the focus of localization of the organisms appears to 
be very circumscribed. Cases of pneumonic plague which develop 
sporadically during epidemics of the bubonic type do not as a rule 
appear to spread rapidly; on the contrary, during epidemics in which 
the pneumonic type predominates the infectivity from man to man is 
' .Jour. Infcc. Dis., 1912, IC, (U: Pvihlic Ik-alth BviW., April, 1911, No. 4;i: ibid., Jan- 
uary, 1912, \>. 53. 
2 Jour. Infec. Dis., 1914, 15, :«1; Jour. Am. Med. Assn., 1914, 63, 2041. 
^ See Tularemia, p. 449 for full details. 
4 Albrecht and Ghon: Centralbl. f. Bakteriol., 1899, 26, .362, 
