NOVEMBER 29, 1906 | 
and the result is a slender, worm-like creature which pro- 
gresses by gliding movements, and which penetrates into 
the wall of the mosquito’s stomach, and there multiplies 
to form an immense number of very minute germs, pro- 
ducing a small tumour on the outer side of the wall of 
the stomach. After a time this tumour bursts, and the 
little germs pass into the blood of the mosquito. They are 
carried to and fro in the mosquito’s blood circulation, but 
ultimately pass into its salivary glands, and the mosquito 
is now infectious. When it next feeds, a swarm of the 
malarial germs passes down its proboscis into the puncture 
it makes, and in this way the disease is passed on from 
one person to another. 
The second important discovery mentioned above, that of 
Smith and Kilborne, concerns a fatal epidemic disease of 
cattle and other animals, sometimes termed red-water. 
In this case the two American investigators discovered, not 
only the cause of the disease, but the method of trans- 
mission. The parasites are tiny, pear-shaped bodies which 
penetrate the blood corpuscles and multiply there, so that 
two or more parasites may be found in one corpuscle. 
Similar parasites are now known to occur in sheep, horses, 
dogs, monkeys, and rats, but are not known with certainty 
to occur in human beings. 
Smith and Kilborne discovered that the parasites of cattle 
red-water were transmitted by ticks, but not quite in the 
same way as malaria is transmitted by the mosquito. 
When a tick feeds on an infected animal, it does not itself 
become infectious, but gives rise to offspring which are 
capable of infecting healthy animals, so that the parasite 
passes through two generations of ticks. Unfortunately, 
nothing intelligible is known of the development of the 
parasite within the tick, and an important field of investi- 
gation is as yet untrodden. 
[For an account of the third discovery referred to above, 
that of Bruce, see Nature, November 15 (p. 56).] 
Enough has been said, I think, to show that protozoology 
offers a most interesting and important field of investi- 
gation, of which as yet only the fringe has been touched. 
Almost every day brings news of some new discovery in 
this field. There are still, however, many questions to be 
answered relating both to protozoa and to the diseases 
caused by them, especially in the tropics, where insect life 
of all kinds is so developed, and there are so many different 
blood-sucking insects to carry infections of all kinds. 
This brings me now to the concluding section of my 
discourse—what are the problems of protozoology and how 
should they be attacked? The problems that present them- 
selves to the student of the protozoa are principally of two 
kinds. In the first place, there are purely zoological 
problems, such as the recognition, classification, and regis- 
tration of the innumerable varieties and forms of these 
tiny creatures; the tracing out of their complicated life- 
histories and their bewildering changes of form and appear- 
ance during development; and the study of their vital 
processes and reactions to surroundings, as throwing light 
on many problems of cytology, heredity and evolution, of 
psychology and physiology. In the second place, the results 
obtained by the zoologist—that is to say, by anyone work- 
ing according to zoological methods—must be applied to 
the elucidation of questions relating to disease in man and 
beast, in other words, to the requirements of the healing 
art, as practised by the medical man and the veterinary 
surgeon. Here, however, all the zoologist can do is to 
supply a knowledge of facts and principles of which the 
healer can make use, and the final beneficial result must 
be obtained by a collaboration of the investigator and the 
practitioner. 
Although it may be urged with justice that the most 
important outcome of human science is its application to 
human needs, it would be the greatest possible mistake 
to attempt to confine any scientific study to just those 
problems which are thought likely to yield results of direct 
practical importance. Such a course would be _ short- 
sighted in the extreme, and would tend to produce a narrow 
outlook and a limited range of ideas, in the place of broad 
fundamental principles on which to base deductions for 
practical guidance. Thus, to apply this statement to the 
special case of protozoology, the forms most important for 
medicine are those which are parasitic upon man, but it 
would be absurd to study only these forms, first, for prac- 
NO. 1935, VOL. 75 | 
NATURE 
nap ty) 
tical reasons, because it is easier to experiment upon 
animals than upon our fellow-men, and, secondly, because 
the study of many different parasites and their development 
supplies analogies which throw light upon obscure points 
in the life-history of those attacking man. But if we take 
a still wider view, we find that three-fourths at least of 
the protozoa are not parasites at all, but live free, indepen- 
dent lives in various situations. 
It is obvious, therefore, that to understand properly the 
highly-specialised parasitic protozoa we must be acquainted 
with the more primitive free-living forms first and fore- 
most. This conclusion may be illustrated by a few facts 
from the career of the late Dr. Fritz Schaudinn, whose 
recent death at the early age of thirty-five was a most 
deplorable event, cutting off an investigator who, by his 
genius and industry, had won the very foremost place in 
the ranks of protozoologists. The bulk of his work was 
done on forms not of importance from the practical, that 
is to say, the medical, point of view, and yet it is not 
too much to say that his work has modified all our ideas 
upon the protozoa and has built up the modern conceptions 
of these creatures, so that no one at the present time can 
write upon them without taking into consideration the facts 
and principles discovered by Schaudinn, whose work is a 
living demonstration of the practical, as well as theoretical, 
imporance of non-practical scientific study. 
The physician and the zoologist work from points of 
view which, though apparently opposed, are in reality 
mutually helpful. The physician, of course, takes the side 
of the patient, and his only object is to extirpate the para- 
site. The zoologist, on the other hand, identifies himself 
as an investigator with the interests of the parasite, and 
tries to become acquainted with all its migrations and 
changes, studying it for its own sake. In short, the zoo 
logist must deal with protozoa as if he loved them, but the 
medical man as if he hated them. ‘There can be no such 
thing as protozoology studied exclusively in relation to 
medicine. Protozoology must be studied as a science in 
which all knowledge is helpful, directly or indirectly. 
When the protozoologist has worked out his life-histories 
and obtained his results, then the medical man steps in 
and carries off the honey to the medical hive. In this way, 
by the cooperation of the purely scientific investigator with 
the practitioner, we may hope that protozoology may have 
before it a bright future, in which both theoretical science 
and the practice of the healing art may be advanced and 
benefited to an equal degree. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
CampripGe.—The Vice-Chancellor announces that the 
treasurer of the Cambridge University Association has 
recently paid to the benefaction fund of the University 
the sum of gogl., resulting from the appeal for the build- 
ing fund for the new museum of archeology and ethnology. 
This payment, together with 60l. already received by the 
benefaction fund, is intended to form a nucleus of 1oool. 
for the building fund of the museum. The Vice-Chancellor 
publishes also a list of subscriptions, paid or promised, 
amounting altogether to 12,325/., toward the building fund 
of the department of agriculture. 
After considering a resolution of the Classical Association 
in favour of abolishing the Greek grammar paper in the 
previous examination, the board of examinations proposes 
that in part i. of the previous examination (a) the 
separate paper at present set on Greek and Latin grammar 
be discontinued; (b) the time allowed for the two papers 
on the Greek and Latin classics be increased from 24 hours 
to 3 hours, in order that more questions in grammar may 
be set than at present, the questions in grammar to be 
such as arise from or are suggested by the passages given 
for translation; (c) the papers set on the alternatives to 
the Greek and Latin classics be similarly lengthened, with 
the same object; and (d) these changes shall first take 
effect at the examination to be held in October, 1907. 
Sir James Dewar, who will be unable to lecture next 
term, has nominated Mr. H. O. Jones, of Clare College, 
as deputy for the Jacksonian professor of experimental 
philosophy during the Lent term of 1907. Mr. Jones has 
