1894. THE PARASITES OF MALARIAL FEVERS. 199 



accepted. Mannaberg gives an interesting summary of the discussion 

 and of the observations and experiments whereby it has been proved 

 that each fever is the result of its own special parasite, and that by 

 no known means can one species be changed into another. 



Now that the life-history of these parasites has been worked out 

 their true zoological position becomes a matter of interest. Laveran 

 at first assigned them to the vegetable kingdom under the name of 

 Oscillaria malaria ; but this view was promptly abandoned by its 

 author, and he renamed the species Hmnatozoon malaria. Numerous 

 other names have been suggested, such as Hamatophyllum, Hamatomonas, 

 Cystosporon, Hamogregarina, Hamopvotciis, Polyinitus, etc., but the name 

 most generally accepted is Plasmodium, by far the most inappro- 

 priate. Medical men usually refer to the parasites as " malarial 

 Plasmodia." It need hardly be pointed out to biologists how utterly 

 inappropriate this name is ; a plasmodium is an irregular mass of 

 protoplasm containing many nuclei. The figures, reproduced here, show 

 that these bodies have but a smgle nucleus. As Laveran's name, 

 Hamatozoon, was not defined with sufficient precision to allow of its 

 adoption in zoology as a generic term, Mannaberg wisely proposes 

 to use it as a general name for the parasites. 



In regard to the class to which they must be referred, numerous 

 opinions have been held : of these several merit notice. MetschnikofF 

 assigned them to the Sporozoa, and placed them in the same group as 

 the genus Coccidiiim. Antolisei, however, referred them to the 

 Gymnomyxa, while Grassi and Feletti considered them to belong 

 to the subclass Amcebea; of the class Rhizopoda. Kruse, again, 

 referred them to the Sporozoa, and to the class of Gregarines. 

 Danilewsky (4) finally, in agreement with the most generally received 

 opinion, placed them in the Sporozoa, but established for them a new 

 class, the Haemosporidia. Mannaberg, after a careful discussion of 

 the subject and comparison of the characters of the parasites with 

 those of the allied forms of Protozoa, agrees with Danilewsky. He 

 divides the Sporozoa into five subclasses, the Coccidia, Gregarina, 

 Myxosporidia, Sarcosporidia, and the new subclass of Haemato- 

 sporidia. 



The results of these researches are not only of interest 

 biologically but of great practical value, for with a knowledge of 

 the cause, it is possible to apply remedies with greater certainty than 

 of old. One of the most interesting sections in each of the two mono- 

 graphs is that dealing with the action of quinine. This has long 

 been known as the most efficaceous of all medicines, but its power 

 has been assigned to very different methods of action, as, for example, 

 to a stimulation of the nervous system. Binz (5), however, in 1867, 

 laid the foundation of a sounder view by showing that, if Infusoria 

 be subjected to the action of quinine, they are killed, and, further, that 

 this is due to asphyxiation : the alkaloid destroys the power of the 

 Infusoria to take up oxygen. The quinine acts on the Haematozoa 



