III. HAEMAMOEBIDAE IN NIGERIA 
The Haemamoebidae in Definitive Hosts. — The nature of the expedition and its 
objects did not permit of a very extensive and minute investigation into the question 
of the proportion of mosquitoes infected, and the nature of the infection in the 
numerous places visited. During our three months' stay at Bonny, however, a 
number of mosquitoes comprising both Anopheles costalis and A. funestus were 
dissected and examined microscopically. These were obtained from huts in the 
native town, as well as from the European quarters of the two factories at Bonny and 
their outhouses. A total number of two hundred and eighty-one Anopheles were 
dissected, and seven only found to be infected. Roughly, much less than half of 
these were obtained from the native town, and since, in the light of later observations, 
it is very probable that the infected insects came from the native town, it can be 
roughly estimated that, whereas of the total only 2 - 6 per cent, showed infection, 
considering the dilution by mosquitoes from the neighbourhood of the factories where 
no native children dwelt, the percentage of infected mosquitoes in the native town 
probably exceeded six. 
The nature of the infection in the seven Anopheles was as follows : — The exact 
type of parasite — tertian, quartan, or aestivo-autumnal — was difficult to decide. 
(1) One mature zygote, showing typical arrangement of zygotoblasts. 
(2) One large zygote, showing a few granules of fine pigment. 
(3) One mature zygote, with zygotoblasts. 
(4) One zygote about half developed. 
(5) One zygote about five days old. 
(6) Two large zygotes, not quite mature, containing few pigment 
granules. Salivary glands infected. 
(7) Two small zygotes with pigment. 
The great rarity with which ' gametes ' of any type are met with in the blood of 
Europeans in West Africa, and the utmost difficulty experienced in work among 
native children, rendered any experiments requiring the feeding of mosquitoes on 
infected subjects, which it had been our intention to pursue, impossible during the 
comparative short stays we were able to make at different stations. Such investiga- 
tions would require a long stay at one place. 
Haemamoebidae in Intermediary Hosts. — The most striking result of the recent 
scientific expeditions to tropical countries for the study of the aetiology of malarial 
