MEDICINE, RECENT ADVANCES IN. 



iii/.e the connection between the egg-shell and the 

 chicken, or between the feathers and the fowl." 



One of the striking features of the new germ, 

 and probably the one that led Laveran to his 

 identification of it, was the presence of a peculiar 

 dark-brown pigment, which was known to be a 

 characteristic deposit in certain organs, notably 

 the spleen, of malaria patients, which, as we 

 shall see, the germ always begins to manufac- 

 ture industriously as soon as it gets into a red 

 blood-cell. In fact, this pigment appears to have 

 been the clue without which the problem would 

 have been almost unsolvable. 



Laveran's discovery, for a time considered very 

 doubtful by other pathologists, was gradually 



rosette, the red blood-corpuscle, which up to this 

 time has held the parasite together, so to speak, 

 breaks up, and the rosette is liberated into the 

 liquor sanguinis. Here in its turn it goes to 

 pieces, and these little spore-cells float away in 

 the blood stream. The phagocytes immediately 

 eat up the black pigment and many of the spores. 

 A few of the latter escape, however, and succeed 

 in working their way into fresh red blood-cells, 

 w r here they appear at first as pale specks. If these 

 are watched, they are seen to grow rapidly, until 

 they nearly fill the blood-cell, developing in the 

 meantime their characteristic pigment granules, 

 w T hich finally concentrate at the center as before; 

 the protoplasm separates into spores, and a new 



confirmed during the next few years, and it marks rosette body is formed, which eventually breaks 



the first great step in the etiology of the disease, up and liberates its spores as did the original 



Among other things, it explained the great efii- parasite. This process is repeated over and over 



f - i-lJl _ _.* 11 *__ __1_J_' _J1 111 1 111. 



cacy of quinine, until then given empirically. 

 Quinine is a deadly poison to certain microbes 

 among others, to the malaria parasite. 



Nine years after Laveran's discovery, Golgi, of 

 Pavia, succeeded in piecing together the different 

 forms that Laveran had described, and worked 

 out the complete phase of the parasite in human 

 blood. 



There are several varieties of malaria, and in 

 each of them the germ has a different life cycle; 

 but in general plan they are all much alike, al- 



A 



again, each time more of the red blood-cells being 

 destroyed. It has been calculated that about 

 250,000,000 parasites are necessary to cause a 

 well-marked attack of malaria. When a man has 

 once become infected with the germ the latter, 

 although individually very short-lived, is enabled 

 by this process to continue and increase the in- 

 fection, unless the blood is disinfected with qui- 

 nine or the phagocytes get the better of the 

 spores and eat them all up before they have a 

 chance to seek safety in the red blood-cells. 



This series of changes 

 has nothing whatever 

 to do with the spread of 

 the disease, and simply 

 serves to continue it in 

 the individual after the 

 parasite has entered his 

 blood. 



Golgi worked out 

 these stages for the ter- 

 tian and quartan forms 

 of the disease; and two 

 other Italians Mar- 

 chiafava and Bignami 

 did the same for the so- 

 called aestivo-autumnal 

 form, which is the most 

 dangerous of the three, 

 and which, because it is 

 commonest in the trop- 

 ics, is called by Koch 

 " tropical malaria." 



The detailed study of 

 these life histories made 



8 



GROWTH OF THE MALARIA PARASITE IN THE HUMAN BODY. 



A, the quartan parasite; B, the tertian parasite; C, the sestivo-autumnal parasite dr P of blood from a 



I m each series is the spore. Beginning with No. 2 the red blood-cell is shown' patient's finger, to dis- 



isite inside. No. 6 A is the rosette body. Nos. 8 A, 7 B, and 7, 8, and 9 C are cover immediately not 



the forms which serve to continue the disease when drawn into the stomach of the only whether the dis- 

 mosquito, but which have no function as long as they remain in the human body. 



.Nos. 1 to 6 in each group show the comnlp.fft p.volp nf thn o-ovm i fVi/^ v,,i^,^^ uj._ e _* 



though the stages differ somewhat in appearance 

 in the several varieties, as shown above. In 

 the quartan form the mature germ is a mass of 

 pale protoplasm which lies inside the red blood- 

 corpuscle, and practically fills it. Scattered 

 through it are the small characteristic pigment 

 masses. Very soon after the parasite has reached 

 maturity these pigment granules concentrate at 



while the proto- 

 into little elongated cells, which 



the 

 and 



body. Shortly after the formation of 'the 



would follow. This was 

 a wonderful advance, 



and a great achievement for science, but 'it was 

 only half of the story. It still remained to discover 

 where the germ came from, and how it got into 

 the human body. The old notion had been that 

 malaria was due to bad air, as its name implies. 

 Then some agent in the water or the soil of ma- 

 larious districts was suspected. Careful search, 

 however, failed to discover the germ anywhere 

 outside of the human body. It could not be 

 found in swamp water, nor in the air over marshy 

 regions, nor in those unhealthful-looking green 

 scums which have such a bad reputation, but 



germ, however, and as spontaneous generation 



