Anthropometric measurements and measurements of body temperature and latent period for onset of sweating were made in the summer in Okinawa on 7 young male Japanese who were born andreared in Okinawa, subtropical zone (Group O), and 7 young male Japanese who were born and reared in the Main Islands of Japan, temperate zone, but moved to Okinawa in less than three years (Group M). Measurement of numbers of active sweat glands were made on 30 subjects in Group O and 20 subjects in Group M in Nishinomiya.
After staying at rest for 30 min in a room with a temperature of 30 C and 70 per cent R. H., oral temperature and skin temperatures at 10 sites were measured. Sweating was induced by immersing the legs just below the knees and the time of the onset of sweating was determined by measuring the weight of the filter paper mounted on the back which was changed at 2 min intervals. Counting of numbers of the active sweat glands at seven sites was made by the Minor's calorimetric methods after sweating was induced by the foot bath method.
Group O showed a little shorter height, lighter body weight and higher ratio of body surface to body weight than Group M. The skinfold thickness for Group O was thinner than that for Group M. The mean values of oral temperature and skin temperatures for Group O were slightly greater than those for Group M. The mean value of T_or-T_s gradient for Group O was slightly smaller than that for Group M. The mean value of the density of active sweat gland for Group O was greater than that for Group M.These results suggest that the capacity of Group O for non-evaporative heat dissipation is superior to that of Group M, Group O has higher conductive-convective heat transfer coefficient from core to skin than Group M, and the efficiency and capacity of evaporative heat dissipation for Group O are superior to those for Group M.The anthropometrical characteristics, higher skin temperature, higher conductive-convective heat transfer coefficient, longer latent period of sweating reflex, and greater density of the active sweat gland for Group O might be explained as due to a result of long-term heat acclimatization to hot climate.

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A total of 963 individuals in three villages were examined for schistosomiasis by both skin test and schistosome ova detection in stool and urine in 1974. The antigen used for skin test was VBS adult S. japonicum antigen (1 : 10, 000 dilution). Stool and urine samples were examined through the concentration methods. Egg-positive rate was 62.2 per cent in Jipe, 68.0 per cent in Eldoro, 69.6 per cent in Kivalwa. Jipe was infested mostly by S. mansoni, Kivalwa by S. haematobium and Eldoro by both two schistosomes. The egg-positive rate was higher in females than in males in Eldoro. In Jipe and Kivalwa, however, the differences in the rate between males and females were not statistically significant. The rate increased with age in children, reached a peak between the ages of 5 and 14 years and then decreased gradually. The positive rate of skin test was 76.4 per cent in total, higher than that of stool and urine examinations. The skin reaction was weak or absent among many egg-positive children. The skin-test-positive rate increased as the age advanced and reached 95 per cent in inhabitants from 40 years up. The positive rate of skin test was higher among males than females in Jipe. No significant difference in the rate between males and females was found in Eldoro and Kivalwa. Among the egg-positive subjects there was no significant difference in skin reaction between S. mansoni infection and S. haematobium infection. In 1975 stool and urine samples from Jipe, Kivalwa, Kuwahoma and Chala were examined. Kuwahoma proved to be infested by S. haematobium. In Chala schistosome infection was rare. There exist villages infested by S. mansoni and/or S. haematobium in the small area. It seems that VBS adult S. japonicum antigen for skin test and the concentration methods for stool and urine examinations are of use in the epidemiological survey in the areas where S. mansoni and/or S. haematobium infections are prevailing.

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The present study was carried out in the permanent water streams of Lumi River, Irrigation Furrow and Lake Jipe in the Taveta area, Coast Province, Kenya during the dry seasons of 1974 and 1975, and the experimental infection was made at laboratory in Japan.
Freshwater snails collected in the Taveta area were as follows : Biomphalaria pfeifferi (Krauss), B. sudanica (Martens), Bulinus globosus (Morelet), B. tropicus (Krauss), B. forskalii (Ehrenberg), Lymnea natalensis (Krauss), Ceratophallus natalensis (Krauss), Segmentorbis angustus (Jickeli), Gyraulus costulatus (Krauss), Bellamya unicolor (Olivier) and Melanoides tuberculata (Müller).
B. pfeifferi was commonly found in river and irrigation canal, whereas B. sudanica only in lake. Natural infection of Schistosoma mansoni was found in B. pfeifferi, but not in B. sudanica. Both the two species were experimentally proved to be suitable intermediate snail hosts of S. mansoni. Therefore it was indicated that B. pfeifferi is the host snail of S. mansoni in the endemic area along river and irrigation canal while B. sudanica is suspected of playing the role in the transmission of S. mansoni in lakeshore.
B. globosus was commonly found in irrigation canal. Around 10 per cent of the snails proved to be naturally infected with S. haematobium on the conditions that many snails occurred. This snail was also experimentally proved to be susceptible to S. haematobium. B. forskalii was widespread, but the snail density seemed to be low. B. tropicus is well known as the not-intermediate snail host of S. haematobium. Therefore there might be a possibility to contribute only by B. globosus to the transmission of S. haematobium in this area.

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These investigations were carried out in some of the villages around Taveta Town, Coast Province, Kenya, during the dry seasons of 1974, 1975 and 1976. The authors examined 83 wild rodents from villages where there is a high infection rate of S. mansoni and/or S. haematobium. The number and species of the rodents collected were as follows : 41 Pelomys sp., 2 Arvicanthis sp., 6 Dendromus sp., 5 Thamnomys sp., 1 Rattus rattus from Jipe, 4 Pelomys sp., 3 Arvicanthis sp., 3 Mastomys sp. from Eldoro, 1 Pelomys sp., 10 Arvicanthis sp., 7 Mastomys sp. from Kivalwa. Among them, 18 Pelomys sp. (43.9%) from Jipe and 1 Pelomys sp. (25.0%) from Eldoro proved to be infected with Schistosoma flukes. These flukes were identified as S. mansoni on the basis of their morphological features as well as the infectivity to their transmitters. In the experimental exposure of Biomphalaria sudanica to miracidia obtained from Pelomys sp., a number of cercariae were observed. This snail also proved to be infected with S. mansoni from human infection. From these investigations, it was suggested that the creek rodent, Pelomys sp. may play the role as a reservoir host of Schistosoma mansoni in this area.

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