110 REVIEW — TROPICAL MEDICINE, ETC. 



Malaria — These conditions are justified by the following considerations : — 



coniinucd j, The presence of the process in all acute and recurrent infections. 



2. The fact that during the time consumed in conjugation in all other protozoa, provided the conjugation is 

 asexual, many generations of the organism could have been produced by division or sporulation in the usual 

 manner. 



3. The fact that such a resting, or zygote, stage must exist, as proven by the recurrouoe of the infection after 

 the discontinuance of quinine given for long periods of time. 



4. The fact that, in cases which have been treated at once with sufficient doses of quinine and for a 

 sufficiently long period, intra-corpuscular conjugation is never seen, and in such cases relapses are very rare, if 

 they occur. 



5. The presence of numerous large pigmented bodies in the blood in cases in which the process is most 

 marked, both intra- and extra-cellular, and which are not seen in cases in which the process is absent. 



6. The argument from " analogy " which indicates that the significance of the process of asexual conjugation 

 in the malarial plasmodia is similar to the same process in other of the protozoa. 



In the Sudan I have seen one case which certainly suggested an intra-corpuscular 

 conjugation, but there is no proof that it really does occur. Is it possible that the malarial 

 parasites in the Western Hemisphere differ in certain respects from those of the Old World ? 

 It is not at all likely, and yet it is curious that it seems to be only from America and the 

 Philippines that reports concerning this condition emanate. Bwing, it should be mentioned, 

 regards intra-corpuscular conjugation as of rare occurrence and of comparatively little 

 significance. 



The Sergents have described a vermicular, ondoglobular form of the malarial parasite 

 seen in the blood of a native of Algeria, and Billet, ^ commenting on this form, mentions a 

 gregarine stage previously studied by him,'-^* and states that the most favourable time for 

 observing the perfect ha3mogregarine form is at the beginning of the apyrexial period. 

 Billet^ has also described curved, vermicular forms of the quartan parasite assumed by the 

 young schizonts during the first hours of their develojDment. These have less active 

 movements than those of the corresponding form of the tertian parasite and they do not 

 throw out prolongations as do these latter. They eventually develop into the quadrilateral 

 nearly adult schizonts characteristic of the quartan parasite. 



In the blood of a case which had become infected at Taufikia, on the White Nile, 

 I found the curious amceboid forms shown in Plate VII, Third Eeport. A parasite closely 

 resembling a trypanosome will be observed. It differs from the hsemogregarine forms 

 described by Billet, and, as it was the first parasite found in the film, proved, for the moment, 

 puzzling, although clinically the case was one of malaria. On the following day a few 

 crescents were found. Quinine soon caused the disappearance of the endoglobular forms. 



Plehn** records a case of tropical malaria acquired in Togoland, which, afterwards in 

 Germany, following treatment, became a double benign tertian. The probability of the 

 patient having had a latent benign tertian is negatived by the excessive rarity of such in 

 the district from which he came. It would seem that a single species of malarial parasite 

 is able to undergo variations according to the different countries and climates in which it 

 develops. Ziemann,'** however, states that all three forms of malarial parasite occur in 

 tropical Africa, and that all that can be said is that the benign tertian parasite is rarer in 

 the Cameroons (l^l per cent.) than in equatorial Africa, where Koch found it in 10 per cent, 

 of the cases. Plehn's supposition is, therefore, probably faulty. 



One can only note a paper by Billet" on the specific differences between the tertian and 

 quartan parasites, and record his opinion that the quartan fever attacks certain races. 

 Hence he believes there are morphological, clinical and ethnological differences between 

 these forms of the malarial parasite. 



' Billet, A. (April 15th, 1905), C. £. Soc. BiuL, t. LVIII. 



« Billet, A. (June 10th, 1901), Ac. Sc. 



= Billet, A. (1906), C. R. Soc. Biol., p. 1146, t. LX. 



< Plehn, A. (July 25th, 1907), " Zur Prage der Arteneinhoit des Malariaparasiten." Dculsch Mai. Woch. 



^ Zieraann, H. (November 14th, 1907), "Zur Prage der Artenoiuheit dcs Malariaparasiten Bemerkung zu 

 dem Artikel von Prof. A. Plelin." Deulsch Med. Woch. 



° Billet, A. (March loth, 1908), " Preuves en Paveur de la Destruction Speoitique des Hematozoalres de la 

 Pievre Tierce et de la Piivre Quarte." Quoted in Bull, de Vlnslilid Pasteur, p. 194, t. VI. 



• Article not consulted in the original. 



