army, officers, and equipment to fight disease, which annually destroys hundreds of thousands of our people, much as barbarous states or bankrupt European kingdoms play with the provision of an ordinary army and navy. Their forces exist on paper, or even in fact, but have no ammunition, no officers, and no information; and there is no pay for the soldiers or sailors. Dr Schaudinn, on the other hand, is carrying on his researches as an officer of the German Imperial Health Bureau of Berlin; and the account of them was published in the official Report of that important department of the German imperial administrative service six months ago. It is not possible here to give a full report on Dr

FIG. 4.-TRYPANOSOMA ZIEMANNI, SCHAUDINN.

From the blood of the stone-owl, Athene noctua. This phase of the lifehistory corresponds to the 'crescent-phase' of the malarial parasite Laverania.

a, represents a female or egg-cell (macrogamete); b, represents a male or sperm-mother. cell (microgametocyte); n. nucleus; bl. blepharoplast. After Schaudinn.

Schaudinn's work; but it appears that he has studied two distinct species of trypanosoma, both occurring side by side in the blood of the little stone-owl, and already seen, but incompletely studied, by Danilewsky and Ziemann. The second of the two species of trypanosome is in some respects the more remarkable. Schaudinn calls it Trypanosoma Ziemanni; and from the figures which are here given (figs. 4, 5, 6 and 7), copied from his article, with the explanations below the figures, the reader will at once see what Vol. 200.-No. 399.

K

an extraordinary range of form and mode of multiplication is presented by this one species of trypanosome. Space will not permit us to comment on these various phases beyond noting how assuredly such forms would have escaped recognition as belonging to the trypanosome history if seen, before Dr Schaudinn's memoir was printed, by any of our medical commissioners blindly exploring round about the diseases caused by trypanosomes in man and mammals.

One very astonishing and revolutionary fact discovered by Schaudinn we must, however, especially point out. Medical men have long been acquainted with the spirillum,

The full-grown trypanosomes seen in fig. 4 have now been swallowed by the common gnat, Culex pipiens, and are undergoing development in its stomach.

A, shows the spermatozoa, Sp., or microgametes, developing as elongated animalcules from the male cell. The large black mass, x, is the stained nucleus of a blood cell of the owl to which the parasite was adherent. B, shows the now rounded egg-cell, Oo, being fertilised by the liberated spermatozoa, Sp. The fusiform mass on the right is a discarded outer coat of the female trypanosome together with the nucleus, x, of a blood-corpuscle of the owl to which it was adherent. After Schaudinn.

or spiral threads, discovered by Obermeyer in the blood of patients suffering from the relapsing fever of eastern Europe. These were universally and without question regarded as Bacteria (vegetable organisms) and referred to the genus 'Spirochete' of Ehrenberg. They were called

Spirochate Obermeieri; and relapsing fever was held to be a typical case of a bacterial infection of the blood. It is now shown by Schaudinn that the blood-parasite spirochete is a phase of a trypanosome (fig. 7); that it has a large nucleus and a micronucleus or blepharoplast, neither of which are present in the spiral Bacteria; and, further, that it alters its shape, contracting so as to present the form of minute oval or pear-shaped bodies, each provided with a larger and a smaller nucleus. These oval bodies are often engulfed by the colourless corpuscles (phagocytes) of the blood; and it is in the highest degree probable that in this condition they have been observed in some tropical diseases without their relation to the spiral

Further phases of Trypanosoma Ziemanni after fertilisation, which are found in the intestine of the common gnat, Culex pipiens.

a, corresponds to the vermicule phase (ookinete) of the malaria parasite. It is the fertilised egg-cell, now elongated and active in movement. The nucleus is seen, and within the nucleus is the blepharoplast. b and c, elongation and coiling of the ookinete with multiplication of the nucleus corresponding to the formation of the spore-holding cysts of the malaria parasite which are attached to the gut-wall of Anopheles; d, breaking up of the coil into small neutral trypanosomes (neither male nor female). From Schaudinn.

forms being suspected.

The corpuscles lately described by Leishman, in cases of a peculiar Indian fever, are very probably of this nature, as are also similar bodies recently described in Delhi sore. On the whole, it may safely be said that the researches of Dr Schaudinn, of which only a preliminary account has yet been published, have widely modified our conceptions as to these blood

parasites, and must lead to important discoveries in regard to diseases caused by them in mammals and in man.

The facts that wild game serve as a tolerant reservoir of trypanosomes for the infection of domesticated animals by the intermediary of the tsetze fly, and that native children in malarial regions act the same part for the malarial parasite and mosquito, suggest very strongly that some tolerant reservoir of the sleeping-sickness trypanosome may exist in the shape of a hitherto unsuspected mammal, bird, or insect. The investigation of that hypothesis and the discovery of the reproductive and

Forms o small neutral trypanosomes belonging to the series of T. Ziemanni found in the malpighian tubes of the common gnat. That marked a is also found in the owl's blood, where it is introduced by the bite of the gnat and multiplies by fission, eventually giving rise to the full-sized sexual forms of fig. 4. These small elongated forms are what have been called Spirochata, and confused up till now with the bacterial parasites known as Spirillum.

a, neutral Spirocheta-phase showing, n. nucleus and, bl. blepharoplast; b, a smaller individual dividing by longitudinal fission into two; c, a similar individual with the two newly formed fission products extended in line; d and e, further longitudinal fission in progress; ƒ, a smaller Spirocheta-phase; g, resting state or contracted condition of the same; h, resting state of a four-fold individual such as e; i and k, star-like agglomerations (such as are well known in Trypanosoma Lewisii, Brucei, and equinum) due to a coming together of free individuals and not to a fission or budding process. After Schaudinn.

secondary forms of the mammalian trypanosomes are the matters which now most urgently call for the efforts of capable medical officers. But we must not be sanguine of rapid progress, since men of the scientific quality

needful for pursuing these enquiries are not numerous; and those who exist are not endowed with private fortunes, as a rule. At the same time no attempt is made by the British Government to take such men into its pay, or to provide for the training and selection of such officers.

The relations of parasites to the organisms upon or in which they are parasitic, and the relation of man, once entered on the first steps of his career of civilisation, to the world of parasites, form one of the most instructive and fascinating chapters of natural history. It cannot be fully written yet, but already some of the conclusions to which the student is led in examining this subject have far-reaching importance and touch upon great general principles in an unexpected manner.

Before the arrival of man-the would-be controller, the disturber of Nature-the adjustment of living things to their surrounding conditions and to one another has a certain appearance of perfection. Natural selection and the survival of the fittest in the struggle for existence lead to the production of a degree of efficiency and harmonious interaction of the units of the living world which, being based on the inexorable destruction of what is inadequate and inharmonious as soon as it appears, result in a smooth and orderly working of the great machine, and the continuance by heredity of efficiency and a high degree of individual perfection.

Parasites, whether microscopic or of larger size, are not, in such circumstances, the cause of widespread disease or suffering. The weakly members of a species may be destroyed by parasites, as others are destroyed by beasts of prey; but the general community of the species, thus weeded, is benefited by the operation. In the natural world the inhabitants of areas bounded by sea, mountain, and river become adjusted to one another; and a balance is established. The only disturbing factors are exceptional seasons, unusual cold, wet, or drought. Such recurrent factors may from time to time increase the number of the weakly who are unable to cope with the invasions of minute destructive parasites, and so reduce even to extermination the kinds of animals or plants especially susceptible to such influences. But anything like the epidemic diseases of para