MALARIA. 649 



which this bod}^ divides differs in the different types of fever, and there 

 arc other points of difference by which the .several varieties may be dis- 

 tinguished one from the other, but which it is not necessary to mention 

 at the present time. The important point is that the result of the seg- 

 mentation of the adult parasites contained in the red corpuscles is the 

 formation of a large number of spore-like bodies, which are set free 

 by the disintegration of the remains of the blood corpuscles and which 

 constitute a new brood of reproductive elements, which in their turn 

 invade healthy blood corpuscles and effect their destruction. This 

 cycle of development, without doubt, accounts for the periodicity of 

 the characteristic febrile paroxysms; and, as stated, the different vari- 

 eties complete their cycle of development in different periods of time, 

 thus accounting for the recurrence of the paroxysms at intervals of 

 forty-eight hours in one type of fever and of three days in another 

 t3'pe. When a dail}^ paroxysm occurs, this is believed to be due to 

 the alternate development of two groups of parasites of the tertian 

 variety, as it has not been possible to distinguish the parasite found in 

 the blood of persons suffering from a quotidian form of intermittent 

 fever from that of the tertian form. Very often, also, the daily par- 

 oxysm occurs on succeeding days at a different hour, while the parox- 

 ysm every alternate day is at the same hour, a fact which sustains the 

 view that we have to deal, in such cases, with two broods of the ter- 

 tian parasite which mature on alternate days. In other cases there 

 may be two distinct paroxysms on the same day and none on the fol- 

 lowing day, indicating the presence of two broods of tertian parasites 

 maturing at different hours every second day. 



Manson, in his work on tropical diseases, recently published, accounts 

 for the febrile paroxysm as follows: 



In all malarial attacks this periodicity tends to become, and in most attacks actu- 

 ally is, quotidian, tertian, or quartan in type. If we study the parasites associated 

 with these various types we find that they, too, as has been fully described already 

 have a corresponding periodicity. We have also seen that the commenc-ement o 

 the fever in each case corresponds with the breaking up of the sporulatmg form of 

 the parasite concerned. This last is an important point; for, doubtless when this 

 breaking up takes place, besides the pigment set free, other residual matters-not so 

 striking optically, it is true, as the pigment, but none the less ^l-P^^^^^^^ ^^^ 

 liberated; a haemoglobin solvent, for example, as I have -f -*«^- .^^.f .^^^^ * ^^^ 

 this haemoglobin solvent, or whether it be some other ^^.^^ance which tep^^^ 

 genetic agent, I believe that some toxin, hitherto inclose<l m the body of the parasite, 

 oHn the infected corpuscle, escapes into the blood at the moment of sporulat.on 



The peJl^Iicity of the clinical phenomena is accounted for ^y^^^f^^^ 

 the parasite How are we to account for the periodicity ot the para^site? It is true 

 thatThas a life of twentv-four hours, or of a multiple of twenty-four hours; but ^^hy 



a pure intermittent, it is practically useless to iook 

 SM 1900 45 



