128 
PACIFIC SCIENCE, Vol. Ill, April, 1949 
TABLE 1 
Infection of Pseudolynchia canariensis with Haemoproteus columbae in Nature 
FLIES 
DISSECTED 
FLIES 
INFECTED 
NUMBER OF INFECTIONS 
FLIES 
INFECTED 
AGE OF 
HOST 
DATE 
Midgut * 
Salivary 
glands 
3-30-48 
Number 
12 
Number 
5 
5 
2 
Per cent 
41.7 
juveniles and 
3-31-48 
4 
0 
0 
0 
0.0 
adults 
juveniles only 
5-12-48 
9 
4 
4 
2 
44.4 
juveniles and 
Totals 
25 
9 
9 
4 
36.0 
adults 
* In addition to typical oocysts found on the midgut, it may be of interest to note oocysts found on the hindgut of one 
fly (see Fig. 3) . 
blood smears cannot indicate the maximum 
rate of infection with Haemoproteus, they are 
a rapid and accurate method of surveying for 
approximate incidence of infection. The smears 
taken from pigeons and doves were subjected to 
Giemsa’s stain, usually within 24 hours after 
they were taken, and were then examined. Be- 
sides recording the positive and negative smears, 
in every positive smear estimates were made of 
the number of gametocytes infecting red blood 
cells. In making this estimation the actual rate 
of infection in 2,000 or more red cells was first 
tabulated and then calculated in terms of game- 
tocytes per 10,000 red cells. The data for these 
Fig. 1. Intensity of infection with Haemoproteus col- 
umbae in 101 pigeons (based on blood smears). 
observations are shown in Table 2 and Figure 1. 
In addition to the data shown in the table, 38 
juvenile pigeons under 30 days of age were 
all found negative. Two Chinese doves, Strep- 
topelia chinensis, were also negative. 
It is seen that the pigeons have a high rate 
of infection and that this rate is a little over 
two times the rate of infection found in the fly 
vector. Such an incidence in both definitive 
and intermediate hosts indicates an ideal situa- 
tion for the life cycle of the parasite. It should 
be noted that most of the birds examined had 
mild infections. As was expected, none of the 
doves examined showed an infection with the 
pigeon parasite. 
Several experiments were conducted in an 
attempt to transmit the Haemoproteus of 
pigeons to doves. It has been shown by Huff 
(1932) that the Haemoproteus of doves could 
be transmitted to domestic pigeons by the 
pigeon fly. However, the pigeon parasite has 
never been successfully transmitted to doves. 
Experiment I: ( 1 ) . On February 20, pigeon flies 
were collected from juvenile pigeons and 17 were 
placed in a cage with an infected pigeon showing ! 
230 gametocytes per 10,000 red cells. 
(2). On February 29, 10 flies were recovered from 
the pigeon and five were placed on a Chinese dove, 
Streptopelia chinensis ( Scopoli ) . This dove had been 
captured on February 2, and blood smears taken on 
February 2, 15, 22, and 29 were all negative for 
