ABSTRACTS AND REPORT.

A LEUCOCYTOZOON OF THE OSTRICH.

IN November I9I1 the author was asked to undertake some investigations with regard to the cause of death among ostrich chicks. Birds had been dying on various farms in the Middelburg district for some time, the majority of deaths occurring among birds from six to eight weeks old. The following figures show the mortality of the disease on the farm where the investigations were made. In T9I r 63 per cent. of 748 birds died, and in the previous year the mortality was about 53 per cent. In I909 the losses were very slight, only five birds dying out of 365. Some of the farmers ascribed the deaths to invasion by worms, and others to the so·called "yellow liver disease," but in many cases it was quite impossible to arrive at even a probable diagnosis.

The author examined a number of birds from six to eight months old and observed the following symptoms: Loss of appetite, poor condition, and paleness of the mucous membrane of the mouth. The bare parts of the body, and particularly around the eyes, were bluish in colour; the diseased birds lagged behind the healthy ones. Death usually occurred some days after the onset of symptoms.

A number of post-mortems were made, and in some cases the deaths of the birds could be referred to the presence of parasites (strongyles and tape worms), but in other cases no parasites were present. Inquiry showed that no changes had been made in the rearing or feeding of the birds.

Examination of the blood revealed the presence of a leucocytozoon. Numerous examinations of the blood of wild birds in the laboratory at Onderstepoort had revealed the presence of parasites of this kind in the blood of certain types of hawks only, and they were consequently thought to be of a slight economic interest.

In blood smears dry-fixed and stained with Giemsa two forms of the parasite can be found which probably represent the male and the female gametocytes. Of the two, the female gametocyte occurs in the larger number. This parasite is more or less rounded in form, but in some cases appears to have an irregular outline which is probably due to distortion, caused by the spreading of the blood films. The parasites vary from 9 to I5 microns in diameter j the cytoplasm stains more intensely than that of the male gametocytes, and contains a number of metachromatic granules which are more distinctly visible in some individuals than in others. In addition to the granules the cytoplasm contains a number of vacuoles. The position of the nucleus is variable, but it is generally found either in the centre or close to the rim of the parasite. The nucleus is composed of a collection of small chromatin particles. In the majority of cases there is a large granule of chromatin either among the small chromatin particles or at a little distance from them. Abnormalities are always to be observed in connection with the nucleus of the host cell. In the majority of cases it is enlarged and elongated, and is in contact with the p:uasite.

The majority of the male gametocytes are round, but the shape is some­what variable. They meaSUIe from 4 to 9 microns in diameter. The cyto­plasm stains faintly. The chromatin granules of the nucleus are generally arranged in a regular manner and are very large. The nucleus of the host cell is, as a rule, not so large as is observed· in the cells invaded by female

ABSTRACTS AND REPORT.

parasites. Contrary to what has he en observed in other birds, no spindle­shaped parasites have been seen in the ostrich. A table is given showing the results of blood examination of a number of birds. The author draws the following conclusions from his investigations: (1) The leucocytozoon is not found in old ostriches; (2) the youngest chicks found to be infected were four weeks old and the oldest seven months; (3) as the deaths did not occur at all farms, and as the presence of leucocytozoon was not demon­strated on all farms, it is impossible at the present moment to declare that this parasite is the cause of the disease. The author suggests the name leucocytozoon struthionis for the parasite. (Walker, Zeitschr.f. Inf!ktionskr. usw. d. Haust., Vol. XII., No. 4, 26th November 1912, pp. 37 2-375.)

THE INVASION OF ANIMAL PARASITES BY BACTERIA.

DURING the process of testing swine·erysipelas serum on mice inexplicable results are often observed, in that animals receiving large doses of serum die of swine erysipelas while others receiving " smaller doses survive. The author undertook the examination of such mice. Of thirty·eight animals which received a dose of '01 to '015 cc. of serum and '01 of culture, and which died, sixteen were found to he the hosts of cysticercus fasciolaris. Microscopic examination showed that in every case large numbers of swine­erysipelas bacilli were present in the scolex and in the fluid contained in the cyst, and the organism could be obtained from these in pure culture. Mice which were infected with the bacilli cultivated in this way died of swine erysipelas in two days. In one case a cysticercus was triturated with 2 cc. of physiological salt solution, 1 cc. of which was injected into a mouse. Death occurred from swine erysipelas on the third day. Further investigations are necessary to determine whether the bacilli multiply within the parasite and re-infect the host.

In three cases ascarides were found in the stomach and intestine of swine-erysipelas mice. These were triturated with salt solution and injected into other mice. Death did not occur, although swine-erysipelas bacilli were demonstrated microscopically.

In one mouse which had been inoculated with the bacillus suisepticus six specimens of cysticercus fasciolaris were found in the liver. The bacilli were found in each of these, and when used for the inoculation of other mice showed an exalted virulence. A dose of '00001 cc. of fluid from the cyst killed a white mouse in eight hours. In the case of mouse typhoid the virulence of the organisms cultivated from the cysticerci remained constant. Two specimens of cysticercus fasciolaris were found in a white mouse inoculated with the streptococcus of strangles, and died within four hours. Microscopic examination showed that the parasites contained strepto­cocci, but there was marked decrease in virulence. In another case strangles streptococci cultivated from a cysticercus had completely lost their virulence (Friedrich, Zeitschr. f. Infektionskr. usw. d. Haltst., Vol. XI!., NO.4, 26th November 1912, pp. 385-386.)

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