338 
parasites bears no relation to the severity of the 
symptoms. 
If necessary, dilute the blood (several c.c.) with 
one per cent, sodium citrate solution, and centri- 
fugalize ; carefully remove with a pipette some of the 
superficial layers of the sediment, and examine with a 
one-sixth inch lens fresh. If not found, the fluid is 
poured off, some fresh citrate added, and the process 
repeated three or four times.* 
2. Blood Changes .—In uncomplicated cases of 
sleeping sickness there is no anaemia (?). As regards 
the leucocytes the changes are not constant. A large 
mononuclear increase up to twenty to thirty per cent, 
has been recorded, and even higher values for native 
blood. On the other hand the increase generally affects 
the lymphocytes, which may reach values of fifty to sixty 
per cent. It is probable that some of these are plasma 
cells, but they have not been so far recorded. The 
possibility of a mononuclear increase from trypanoso¬ 
miasis should therefore be borne in mind in those cases 
of malaria where no parasites are present, but trypanoso¬ 
miasis in doubtful cases is most easily diagnosed by 
gland puncture. The average values of a large number 
of counts made by Greig and Gray give : red cells, 
4,707,000; white cells, 11,000; large mononuclear, 
twelve per cent. ; lymphocytes, thirty-eight per cent. ; 
polynuclears, thirty-nine per cent.; eosinophil, five 
per cent. 
3. Gland Puncture .—Sterilize the syringe and get 
rid, as far as possible, of any fluid in the interior. 
Puncture the posterior cervical glands and move the 
point of the needle about in the substance of the 
gland. Draw out the piston. Now detach the 
barrel only. Next take out the needle. Then, 
replacing the barrel eject the contents, best, into a 
* Koch recommends the frequent examination of stained films made as-thick 
as possible. 
