Observing such a ring with an open Abbe and deflected light, we can see that it makes a deep sharp furrow in the surface of the blood corpuscle, which protrudes into the center like a finger in a ring. From this ring form the parasite may return to the ameboid form; this play often repeats itself several times under the eye of the observer.
The young ameboid parasites show extremely fine pigment dust, often reddish in color. This is entirely at the periphery of the organism, and usually manifests slight movement. After the parasite has grown to about one third .the size of the red blood corpuscle, the pigment collects in the middle or at the margin and the ameboid movement ceases. After concentration, the pigment remains at rest in dark clumps and the parasite breaks up into a few very small spores. The parasites sometimes, too, reach a considerable size, so that at the time of their sporulation they may fill a whole corpuscle.
As Marchiafava and Celli have proved in the mild cases of summer fever of intermittent, quotidian type, so, too, in these the concentration of the pigment and the sporulation occur simultaneously with the fever paroxysm. Those observers also discovered the sporulation forms of these parasites, and demonstrated that the sporulation does not take place in the peripheral blood, but in the internal organs. As a consequence, therefore, during the paroxysm, even in cases of severe infection, none at all or only a few segmentation forms are found in the blood from the finger, while large numbers are seen in the blood from the spleen.
The discovery, in the peripheral blood, of a number of large parasites containing pigment clumps is a positive indication of the approach of a paroxysm. This is also true for the malignant tertian parasites. After the paroxysm the non pigmented small rings are found.
The infected red blood corpuscles frequently shrink and then assume the color of old brass. Marchiafava and Celli believe that the parasites inclosed in the "brassy corpuscles" are degenerated forms. On account of the structural staining, which shows the nucleolus deeply stained, I cannot support this view.
These infected shrunken blood corpuscles may lose their color completely and become extremely delicate, veil like, and wrinkled. The "brassy corpuscles" should not be confused by the inexperienced with the "morning star" or "halberd" forms. To differentiate them it is only necessary to remember that the parasite is always to be seen in the case of the "brassy corpuscle," being usually in the form of a small hyaline ring stamped on the "brassy corpuscle" in a manner which cannot be mistaken.
After the disease has existed for some days we see, in addition to the already described forms, others belonging to the order of crescents. These are: (1) The typical crescent shaped bodies; (2) spindle shaped forms, pointed at the ends (cigar forms); (3) spheres.
A detailed description of the morphology of these forms and mode of origin has already been given in previous sections.
In illustration of the connection between the clinical and microscopic phenomena of these cases the following history is reported:
K. St. has suffered daily for a week with paroxysms of fever which occurred about 4 p. m., and consisted only of a hot stage. The patient is very weak, unable to walk, and had to be carried to the hospital. Marked pallor, typhoidal condition. The teeth are dry, the papillse at the tip of the tongue swollen, the posterior half of the tongue covered with a thick grayish coating. The spleen is evidently palpable. Pulse 110, dicrotic, tension normal. Two or three thin liquid stools daily.
August 4, 1892, 5 p.m.: Temperature, 38°.
Blood examination: 1. A few small ameboid, non pigmented organisms. 2. A large number of melaniferous leukocytes. August 5, 9 a.m.: Temperature, 37°.
Blood examination: 1. A very few organisms of medium size, filling one fourth to one third of the blood corpuscle, and containing one clump of pigment. 2. Isolated "brassy corpuscles"; no melaniferous leukocytes.
4 p.m.: Temperature, 38.2°.
Blood examination: 1. Isolated, small pigmented organisms. 2. One crescent with concentrated pigment. 6 p.m.: 0.66 quinin.
August 6, 7 a.m.: 0.66 quinin.
10 a.m.: Temperature, 36.5°. Patient considerably prostrated, tongue dry and brown.
Blood examination: 1. Isolated crescents. 2. A moderate number of melaniferous leukocytes.
4 p.m.: Temperature, 35.4°; general condition as before.
From this time on no other paroxysms took place, and the condition, previously so threatening, improved rapidly.
In this case we must remark the disproportion between the small number of parasites, the slight elevation of temperature, and the severity of the other symptoms. The crescents appeared on the eighth day of the disease.
As mentioned previously, crescents, and the organisms belonging to this class, appear usually in the blood only some time after the beginning of the disease. Moreover, they are found there occasionally in association with isolated ameboid organisms even during the apyretic period. When these are seen in the blood of a patient, we can draw the positive conclusion that paroxysms of fever must have occurred a short time before. As long as the crescents and their spheres remain the only features of the blood, there is, as a rule, no fever. In fact, the Roman school holds that these organisms are incapable of causing fever, and that when paroxysms occur, endoglobular ameboid organisms must also be present. Marchiafava and Celli have seen cases with large numbers of crescents in the blood without rise of temperature. Other investigators have made similar observations. My own experience agrees with this for the great majority of cases, yet I must add that I have met several with moderate paroxysms of fever in which I have searched in vain for the ameboid organisms. It is naturally possible that these were present not in the peripheral blood, but only in the vessels of the internal organs; and I consider this assumption very probable. Nevertheless, from the standpoint of clinical medicine, these cases cannot be passed over, and I will, therefore, take occasion to detail a few from this category among the following histories. Still I can affirm that it is the rule for the fever to be wanting when crescents alone are present. Yet in spite of this the patient is frequently in a more or less cachectic condition and the lessened amount of hemoglobin and the decreased number of corpuscles in association with it improve slowly or not at all; in fact, sometimes become worse.