18

Examination of population of “ B. Non-Sleeping Sickness Areas,” showed that the incidence of gland enlargement was low.

4. • Lymphocytosis occurs in all cases of sleeping sickness.

Enlargement of lymphatic glands being a constant feature in sleeping sickness, it was a matter of importance to determine whether the lymphocytes in the blood show an increase in numbers. This point is of interest further, because the most constant lesion found in the nervous system of sleeping sickness cases is an accumulation of cells of this nature in the perivas­cular lymph spaces.

In uncomplicated cases of sleeping sickness anæmia does not occur, the number of the red cells and the percentage of haemoglobin being normal. ‘Towards’ the end, in a certain proportion of cases, the number of red cells, the percentage of haemoglobin and the specific gravity rise above the normal. These cases did not present any signs of cyanosis. The examina­tion of the bone marrow in one of these cases showed a very large number of nucleated red cells, chiefly normo-blastic, but some megalo-blasts were also present.

• Mast cells were present in the blood of all cases to the extent of about 1 per cent.

The eosinophiles, also, form a higher proportion ot the leucocytes than is normally met with.

The examination of the blood was made by means of a Thoma-Zeiss blood counting apparatus and a Gowers’ liæmoglobinometer.

It was also found that the trypanosomes were more numerous in the blood at night time.

The following table shows the result of the enumeration of the blood cells and the percentage of hæmoglobin in 57 cases of sleeping sickness :—