36 Proceedings of the First Convention 



perate and torrid zones in the next few years confirmed his 

 discovery. To-day inteUigent medical students, even after a 

 single lesson in the technique of blood examination, can dem- 

 onstrate the germ. On the other hand, when the germ is absent 

 after a properly conducted blood examination the malady in- 

 variably proves to be some other disease than malaria. More- 

 over, if human blood infected with this parasite be injected 

 into a healthy man, the germ multiplies in the new subject and 

 in from nine to fourteen days he sickens with the same charac- 

 teristic and periodic chill, fever and sweat shown by the pre- 

 vious patient. 



The life history of the malarial parasite (of which there are 

 several species) being further worked out, the important addi- 

 tional fact was discovered that the germ takes a definite num- 

 ber of days in which to grow to full size, — that when of full 

 size it splits up or sponilatcs into a fairly definite number of 

 small segments, and that these young germs burst the parent 

 blood cell and are set free in the blood, soon entering other 

 cells heretofore healthy, and ultimately repeating exactly the 

 process just described. In most cases a vast majority of the 

 parasites are of the same age, and a chill and fever invariably 

 ensue within an hour or less after each crop of full-grown germs 

 had been shown under the microscope to begin to sporulate. 

 Every logical canon of experimental science is thus satisfied. 



The next link in the chain of evidence began to be fashioned 

 when it was found that besides those germs which sporulate 

 at regular intervals in the blood, other germs appear which, 

 though of nearly the same size as the sporulating forms, 

 take up aniline dyes in a different way and are never seen to 

 segment, but only at times to send out one or two or more long 

 vibrating threads. The threads (technically called flagella) do 

 not appear till the blood has been drawn from the body, i. e., 

 till the germs are subjected to a chemical or mechanical stimu- 

 lus other than any received in the blood vessels. Already, as 

 early as 1895, this process (with something akin to an intuition 

 of genius) was interpreted by Dr. Patrick Manson of London 

 as having to do with an alternate mode of reproduction. He 

 ventured the prophecy, basing his induction upon similar bio- 

 logical processes already known, that the body of some blood- 

 sucking insect (most likely a mosquito) would be found to 

 be the sphere of development of a new generation of malarial 



