588 TREPONEMATA, SPIRONEMATA, LEPTOSPIRATA 
just to the boiling-point (when bubbles pass from the bottom of the 
flask to the surface). Remove from the flame, and add drop by drop 
(not more than 0.2 cc. at a time) exactly 4 cc. of the formalin solu- 
tion (3). Continue shaking until the color change passes from a faint 
purple through a deep purple-red to a red-brown color, which remains 
permanent. Such a solution should be clear, of a deep Bordeaux red, 
and it should be protected from dust and the light. 
A 1 per cent NaCl solution (1.7 cc.) should effect complete precipi- 
tation of 5 cc. of the colloid in one hour. 
A test should also be made with a known cerebrospinal fluid from a 
case of general paresis, in comparison with a known colloidal-gold 
solution that has given satisfactory results. 
TREPONEMA PERTENUE. 
Synonyms.— Spirillum pertenue; Treponema pallidulum. 
Castellani^ has reported the constant association of an organism 
which he called Spirillum pertenue, in frambesia tropica (Yaws). 
Frambesia is a specific infectious tropical disease characterized anato- 
mically by peculiar specific granulomatous eruptions. The disease, 
like syphilis, presents three stages: (1) a primary lesion, which is a 
papule situated at the site of infection— this papule becomes indurated 
and, may ulcerate; (2) a generalized eruption, papular in character, 
which gives rise to characteristic granulomata; this may appear 
after the primary lesion has healed— the disease frequently ends at 
the second stage; (3) tertiary stage, characterized by gumma-like 
processes which may undergo deep ulceration. Recent studies by 
Butler (see nifra), indicate that yaws is a form of syphilis. 
Morphology.— Treponema pertenue is a very delicate, slender spiral 
organism, measuring about 0.3 to 0.5 micron in diameter, and from 
6 to 18 microns in length. The ends of the organism are frequently 
pointed, but one or both ends may be rounded, or, rarely, somewhat 
swollen. There are usually from 6 to 20 spiral turns in each organism. 
Blanchard^ states that the organism possesses an undulatory membrane, 
but the consensus of opinion is against this view. Very delicate polar 
flagella, one at each end, have been demonstrated by flagella stains. It 
will be observed that the size and arrangement of the organism do not 
dift'er essentially from that of Treponema pallidum. The organism 
fails to stain by ordinary methods, but the morphology is well brought 
out by Giemsa's stain. Treponema pertenue may be demonstrated 
by the methods applicable for Treponema pallidum. It has never 
been cultivated in artificial media. It is probably the same organism as 
Treponema pallidum.^ 
Specificity of Organism.— Many experiments have been performed 
which are supposed to show^ by inoculation that yaws and syphilis are 
1 Lancet, August, 1905; British Med. Jour., 1905, ii, 1280, 1330, 1430. 
2 Arch. d. Parasit., 1906. 
3 Butler and Peterson: Jour. Lab. and Clin. Med., 1927, 12, 670. 
