628 
THE TROPICAL AGRICULTURIST. [Fee. 1, 1901. 
A peculiar disease was .said to occur at Saipan, 
the course of wliich, with fever and lasting para- 
lysis of certain limbs, could not but awaken the 
suspicion that it was beriberi. Of the patients 
of this kind who were shown to me one was sufter- 
ing from hemiplegia, others from articular or 
muscular rheumatism. There was .not a single 
indubitable case of beriberi. On the whole I got 
the impression tliat, as the islands of Ponape and 
Siipan are free of malaria and also of other 
tropical diseases except yaws, their hygienic 
condition is very good. From Hongkong we 
•went by the main line of the North 
German Lloyd to Suez, where we broke 
our journey, in order to make a short stay in 
Egypt. Tlie purpose of our visit to Egypt was 
to "find some explanation of the contradictory re- 
ports about the malaria there. This purpose 
was partly gained, for we found in Alexandria 
BBveral cases of malaria which had indubitably 
originated in or near that city, and genuine 
topi of endemic malaria at Heluan near Cairo and 
at Wadi Natrun, west of the Delta, in the midst of 
the desert. According to the last news I have 
received from Stephansort, dated the 8th of 
August, the favourable state of malaria there 
described in my reports had remained unaltered. 
In order to pave the way for the repetition 
in Germany of the experiment that succeeded 
so well in New Guinea, Professor Frosch, who 
•was at one time a member of the n^alaria 
expedition, has visited many apparently suitable 
districts in INorth Germany, and made careful 
investigations with a view to ascertaining whether 
there is any malaria there. He found everywhere 
that malaria is rapidly dying out. At many 
places which used to be notorious malaria-foci the 
disease has almost entirely vanished ; at others 
(in the marshy lands on the North Sea coast for 
instance) only isolated cases occur ; nowhere 
could a malaria-focus suitable ior my purposes be 
^°XJnder these circumstances nothing remained but 
to conclude the work of the malaria expedition 
for the present. 
Berlin, Nov. 17.— On the 15th instant Profes- 
sor Kobert Koch spoke to the Berlin and 
Charlottenburg section of the German Colo- 
nial Society on the results of the malaria 
expedition sent out by the German Em- 
pire. The meeting took place in the hall of 
the Kaiserhof (one ot the biggest hotels in Berlin), 
and consisted largely of medical men, officials of 
the Colonial Department and officers of the army 
and navy. Koch was welcomed with loud applause. 
He began by thanking the Colonial Society for 
8U"gesting the malaria expeditions, and then 
stated what is now known about malaria. The 
gist of his lecture was this : 
The germ of malaria, first seen by Laveran, is 
an animal organism, which lives in the blood of 
the malaria-patient and is so characteristic that 
the discovery of even one such parasite in a 
person's blood justifies the opinion that he has 
malaria. There is a whole group of malaria-para- 
sites, and a corresponding group of malarial 
diseases. Germany has two kinds of malaria, 
Italy three, and a fourth kind, tropical malaria, 
is found in the tropics. The parasite can live 
long in a human body. Malaria reveals itself in 
1 series of attacks each of which is the conse- 
nuence of a fresh proliferation of germs. The 
yiolence of the attacks diminishes in the course 
of the disease, but relapses take place, sometimes 
even after the lapse of years. The question how 
the parasites get into the blood used to be 
answered in several very different ways. Now 
it is known that they are conveyed from one 
human body to another by gnats. This discoverj 
is due to an observation of Ross, who demon- 
strated that the germs of malaria undergo a 
long process of development in the stomachs 
of gnats. The microscope shows that the deve- 
loped germs meet in the poison-gland 
ot the gnat. When a gnat sucks a human beinff's 
blood it empties its poison-gland, and thus intro- 
duces the parasites into his blood. In August, 
1898, a German expedition was sent to Italy to 
test Ross's statements, and was soon able to con- 
firn) them. It was also ascertained that the 
apparently different Italian forms of malaria are 
really one, that Italian malaria is identical with 
tropical malaria, and that, apait from quartian 
and tertian which occur among ourselves there 
really is only one form of malaria, namely tropical 
malaria. 
In the spring of 1899 the German expedition 
went to Italy again, and took up its abode at 
Grosset, in the Tuscan Maremmae. Spring was 
chosen, because it is in spring that malaria 
breaks out afresh in Italy, At first there were 
few cases, and these were relapses of cases ef 
the year before. Not till the weather became 
warmer did the first fresh cases occur, but then 
their number increased very rapidly. They were 
uncommonly severe too, but the patients were 
taken to the hospital so promptly that the system- 
atic treatment with quinine could begin in good 
time, and consequently the number of deaths was 
comparatively small. In autumn, after raging 
for four months, the malaria died out. Now, 
why is it that no fresh cases of malaria occur 
in Italy in winter, though there are gnats 
there in winter too ? The reason is that 
the real home of malaria-germs is the body of 
a malaria-patient ; they winter there. But 
the human body is not only the real home of 
malaria-parasites, it is also their only home. In the 
blood of monkeys, birds, and bats, indeed, orga- 
nisms strongly resembling malaria-parasites are 
found, but closer examination shows that they 
differ from them. That the malaria-parasite 
thrives only in the human body is also proved by 
the fact that malaria is not transferable to an- 
thropomorphous apes. The way in which malaria 
is propagated is this : a human being with malaria- 
parasites is stung by a gnat, which thus imbibes 
malaria-germs, which then develop in it, and are 
introduced into the blood of another person whoa* 
it stings. The anopheles is the chief bearer of 
malaria-parasites, but it is probable that other 
kinds of gnats (the pulex for instance) play a part 
in the business. It follows that in the battle 
with malaria the point of attack must be the 
malaria-patient. 
The expedition then went to Java, and from 
there to New Guinea. Notwithstanding the 
great resemblance between the physical and 
biological conditions of those two islands, they 
differ most strikingly. Wherever you go in 
Java you see the fruits of prosperous human 
labour ; in New Guinea hardly a trace of it. 
But the history ot Java teaches that New 
Guinea too may be made to blossom like the 
rose. All that is necessary is the judiciously 
managed colonisation of the country, and the 
poly hindrance (but it is a most formidable one) 
