529 
it appears to me that the greatest hope of success in combating malaria 
lies in the distribution of quinine. It would then make no difference how 
numerous the Anopheles might be, they would be harmless if the native 
were rendered free from the plasmodium by the use of quinine. 
INTRACORPUSCULAR CONJUGATION. 
In concluding these observations upon malarial infection I desire to 
call attention to intracorpuscular conjugation, a phase in the human 
life cycle of the malarial plasmodia, which I believe to be of the greatest 
importance, and which makes clear many obscure points in the clinical 
history of malarial infection. 
This process was first mentioned by Mannaberg, but described more at length 
by Ewing’ in 1901.) Ewing concluded that, while conjugation of the malarial 
plasmodia undoubtedly occurred in the red blood corpuscles of man, it was ‘by 
no means constant and probably of no essential importance in the human life 
cycle of the plasmodia. In a later contribution he states that the process may 
favor the multiplication of the plasmodia in the human host and that its disap- 
pearance tends to limit the malarial infection. 
For nearly five years I have devoted much study to this process and 
have observed it in hundreds of cases. My results are given in detail in 
a recent publication® and at the present time I will only very. briefly 
discuss the subject. 
The process of intracorpuscular conjugation, as seen in the malarial 
plasmodia, is not a sexual act, for no difference in sex can be distinguished 
in the conjugating bodies. It is a process which is very common in many 
classes of protozoa and is intended to preserve the reproductive power of 
the organisms in which it occurs. By continued division, many of the 
protozoa eventually become exhausted and to prevent this result, con- 
jugation occurs, the two conjugants, which are not sexually differentiated, 
becoming one, thus bringing about a restoration to former reproductive 
activity, due to a “rejuvenescence” of the vital activities of the organism. 
In what way this “rejuvenescence” results we do not know, but there can 
be no doubt but that if it were not for this interesting process many of 
the protozoa would cease to exist. In the case of the plasmodia of 
malaria, conjugation is a phase of the human life cycle and it occurs 
within the red blood corpuscles. It essentially consists in the permanent 
union of two hyaline ring forms, or hyaline bodies, is always complete 
before the development of pigment takes place and it oceurs in all the 
species of malarial plasmodia. — + 
The process may roughly be divided into three stages. In the first one 
the two hyaline rings are in contact, and in stained specimens it will be 
* Journ. of Exper, Med. (1901), 5, 429; Clinical Pathology of the Blood (1903), 
454, ' ig 
*Intracorpuscular Conjugation in the Malarial Plasmodia and Its Significance, 
Amer. Med. (1905), 10, 982-1024. 
42210 —7 
