298 



SCIENCE. 



[Vol. VII., No. 165 



multiplies abundantly at certain seasons of the 

 year, when conditions are favorable as to tem- 

 perature, etc. 



The general belief among physicians that there 

 is a malarial germ, is, perhaps, the reason for the 

 somewhat numerous pseudo - discoveries which 

 have been announced. The most recent of these 

 is the Bacillus malariae of Klebs and Tomassi- 

 Crudeli. These gentlemen, in 1879, made re- 

 searches in the vicinity of Rome, as a result 

 of which they announced the discovery of a 

 bacillus which they believed to be the veritable 

 malarial germ. The evidence upon which their 

 claim was based was obtained by experiments 

 upon rabbits. The writer, in 1880, repeated their 

 inoculation experiments with material obtained 

 from the swamps in the vicinity of New Orleans, 

 and showed that the fever which results from 

 such inoculations does not correspond with the 

 typical malarial fevers of man, and is, in fact, 

 simply a form of septicaemia. 



Nevertheless the Bacillus malariae received con- 

 siderable credit in this country and in Europe, 

 and many physicians were disposed to place it in 

 the category of demonstrated disease-germs. On 

 the other hand, the claim of Laveran received 

 comparatively little attention. Among those who 

 presented evidence in support of the malarial 

 germ of Klebs and Crudeli was Professor Marchi- 

 afava of Rome. This gentleman has since con- 

 tinued his researches with reference to the cau- 

 sation of the malarial fevers, and finds himself 

 compelled to abandon the Bacillus malariae. In- 

 deed, I found no one in Rome who any longer 

 attaches faith to this alleged discovery. But as a 

 result of very extended observations, made in 

 association with Dr. Celli of Rome, Marchiafava 

 now fully confirms Laveran as to the presence of 

 an amoeboid organism in the blood of patients 

 suffering from malarial fever. Similar testimony 

 had previously been given by Richard, a French 

 army surgeon, who had excellent opportunities 

 for such researches at Philippsville in Algeria. 

 Space will not permit me to give a detailed ac- 

 count of the researches of the>e gentlemen, or 

 of the different forms in which the parasite is 

 said to present itself. The accounts show that 

 it differs from all disease-germs heretofore dis- 

 covered, inasmuch as it does not belong to the 

 bacteria, and is not even a vegetable parasite. 

 It is an extremely minute amoeboid organism, 

 which is found free in the blood, or in the in- 

 terior of the red blood-corpuscles (Marchiafava 

 and Celli), or attached to them (Laveran and 

 Richard). In a certain stage of its development 

 it possesses from one to three or four flagella, and 

 is endowed with active movements. But all of 



the observers agree that this form is not very 

 frequently encountered. Marchiafava and Celli 

 only observed the flagellate organisms in four 

 cases out of forty-two, in which the blood was 

 carefully examined. 



The accompanying figure is copied from the 



Figs. 1-29 represent the changes in form which occurred in 

 a Plasmodium, contained in a red blood-corpuscle, dur- 

 ing a period of twenty minutes. Figs. 21-27 give some 

 other forms which the Plasmodia, both with and with- 

 out pigment, may assume. Fig. 28 represents a motion- 

 less Plasmodium which is emerging from a red blood- 

 corpuscle (the blood was examined after the attack of 

 fever and the administration of quinine). 



latest paper 1 by the gentlemen last mentioned, 

 and represents the parasite as seen in the interior 

 of the red blood-corpuscles. 



As mentioned at the outset, the writer had 

 ocular evidence of the presence of such an amoe- 

 boid organism in the blood of a patient sufferini 

 from a malarial fever, during a recent visit to 

 Rome. Passing through the wards of the Santo 

 Spirito Hospital with Dr. Celli, a case was selected 



1 ' Weitere untersuchungeu iiber die malariainfection,' 



in Friedliinder's Forschritte der medicin, Dec. 15, 1885. 



