ECOLOGY, COMMENSALISM AND PARASITISM 407 



called tropical malaria, combined with the aberrant form of the 

 gametocytes, was sufficient justification for a different generic name. 

 That the point was well taken is shown by the fact that today there 

 are two camps: one, supported bv Reiehenow-Dofiein, maintains 

 the position of Grassi and Feletti, and recognizes the genus Laver- 

 ania; the other, supported by Welch, Schaudinn and Wenyon, 

 cannot see that the shape of the gametocytes with the somewhat 

 more virulent clinical history is sufficiently important to justify a 

 different generic name and, following Welch (1898), the third 

 species was named Plasmodium falciparum. A similar difference 

 of opinion concerns the generic name of the organisms causing bird 

 malaria. Some authorities, following Labbe (1894), use the generic 

 term Proteosoma; others cannot see that, other conditions being 

 the same, a difference in hosts is of sufficient zoological importance 

 to warrant a different generic name and the bird organisms are 

 also grouped under the generic name Plasmodium. Following the 

 example shown in connection with the genera Trypanosoma and 

 Endameba, it would seem that the weight of authority rests with 

 the advocates of the name Plasmodium. 



Although Laveran's original discovery attracted much attention, 

 the organism was not immediately accepted by pathologists as the 

 cause of malaria, and it was only after careful work of the Italians, 

 Marchiafava, Celli, Grassi, Feletti and especially of Golgi (1886), 

 that the relationship was established. Golgi, beginning in 1885, 

 correlated the clinical picture of malaria with the developmental 

 stages in the intracorpuscular history of the parasite. 



The transmission of malaria from individual to individual was 

 another story. R. Pfeiffer (1892) was struck by the resemblance 

 in their life histories, of Plasmodia and Coccidia, and, not finding 

 sporocysts and oocysts in the former, suggested that malaria organ- 

 isms might be transmitted from host to host by some blood-sucking 

 insect. Laveran in the same year and Manson in 1894 indepen- 

 dently advanced the same idea, and each suggested the mosquito 

 as the transmitting agent. These suggestions were brilliantly 

 proved, first in France, later in India by Ronald Ross and by 

 Grassi in Italy. Ross (1897), unable to finish his work on human 

 malaria in Paris, continued the work on bird malaria in India, 

 lie proved that mosquitoes of the genus Culex, and no other kind, 

 are capable of transmitting this type of malaria from bird to bird. 

 Grassi (f900) published a classical monograph on the life history 

 of the organism causing tropical malaria (P '. falciparum) , and with 

 beautiful figures of the developmental stages in the gut of the 

 mosquito. Supplementing Ross's observations on Culex, he showed 

 that mosquitoes of the genus Anopheles alone have the power to 

 transmit human malaria. Schaudinn (1902) confirmed these find- 

 ings by working out the life history of Plasmodium vivax, the cause 



