KU .3 Barber et al.: Malaria in the Philippines 199 
positives. A large proportion of positives from these towns 
were latent cases, and the number of parasites found per slide 
was small. Of the total 75 positives only 4 preparations showed 
as many as 1 parasite per leucocyte. The time given to exam- 
inations in these towns is shown in Table V. 
TABLE V.—Time devoted to examination of preparations from Mabitac, 
Santa Maria, Lucena, Tayabas, and the greater part of those of Sini- 
loan. Thick films. 






Negative. Positive. 
Slides Slides 
exam- exam- 
ued ed 
Time examined before the preparation to) . * « ° 
as G@IEWEal HOSEN. qean Time required to find the first parasite. hich 
time time 
was was 
taken. taken. 
Ani NULESe ee eee SS ae Ss Oh immediately =o ee ee a see ee 13 
a2; tor4./b) minitess 2-208 see) ey 230 |"biton O}Second Sj=saaeee see a ee eee ee 4 
byminutess- 226 ea see 33 see 236% (NL bitorZbISeCONnG Sees ces a ee ees 8 
BeZbitojosto nbs ae a a er AST SOKLOMoIseCONUS eae ae eee ee en 13 
Gainiinutes sete: h2n5 3 Sees (SH Mllminuteysss sacar See Se Ae Ec Se See 6 
6:25, to Gc 7ominutess-- sass ee ee 245 ie 2etowlsbiminu tes === aeeeeee ee a eee 10 
TOUTE COS eee ee ST ep SE ee 19h Ohminubest te seas soet eee se Ses ee 3 
TAS) iO) WANS eeovy ons) ee es SMIRZECDICOTAc DEO TELE S sere een eee yes 6 
SamiInutesve = wees es ee ee OF | MSuminutesm-= ses se soe eee eS 2 
S:2b, LOLs. O MUNG ess ee Ie iOe2bitolsepimMin bess a= ee 3 
Ohmi tess=- 2 eee FN oe me! oe ASIAN TUTE Se eee ts er a yee ye ee 3 
OOeMNINU bess aan een eee eee ee eee Da KAS eminuteses— aa es ee ee ee 1 
HOjminiitess= sea Seas ey SS eyes 39220) Ato byminutes 4522 eee ee 2 ee 1 
LOWS ymin utes ss = eee eee di (6iminutes) esis. ee et Se 1 
HOpMINULe se sere a. ase es ee eee) in| Gub minutes. 2. eee oe 1 
(ROWTINIUILGS See ee ee ee eee ene See PAG Pee sees cae 5 teensy d ieee thay eS AEN Bh dels Tak bie ci 
LG Gea i eee eta a EN 463 Totalee cen cee er eee So Rp 




Summary of Table V. 
Time required for 463 negative slides 2,588 minutes. 
Average time per negative slide ; 5.6 minutes. 
Total number of negatives and positives 538 
Percentage of positives 13.9 
There were 538 preparations of which the time was taken. 
Seventy-five, or 13.9 per cent, were positive, and the average 
time of examination of negatives was 5.6 minutes. This may 
be slightly in excess of the average time in all our examinations, 
but had the time of examination for the series in Table V been 
limited to four minutes, we would still have had 13.1 per cent 
positive. If it had been limited to even three minutes, we would 
have had 11.7 per cent positive. So it is evident that the per- 
centage of error is small for the time we actually devoted to 
examination in our series. It must, also, be taken into consid- 
