The localization of Giardia muris was determined in 8 Giardia-infected laboratory mice that were fed on a normal diet. The average total length of small intestine of the mice was 38.3 cm. Among 8 sections (to divide into 8 part from pylorus to cecal junction :Sect. I, Sect. II, ...... Sect. VIII), the optimum habitat ranged Sect. IV to Sect. V(from 14.5 cm to 24.4 cm posterior to the pylorus. Distribution rate of Giardia muris in posterior part of small intestine was higher than that in anterior part. The bile duct of 8 mice were examined, but no Giardia was found. The cyst of Giardia muris were found at the part posterior to the Sect. VII. The result of a comparison between varying average body length and body breadth of Giardia muris drawn at random from different part of small intestine of 5 laboratory mice was as follows : Maximum average dimension of the body length of the trophozoite was found at the part of Sect. IV and minimum average value was observed at the part of Sect. VIII. On average dimension of body length of the trophozoite, no significant difference was obtained among the parasites at Sect. II, Sect. IV, Sect. VI, but significant small dimension value was observed aat Sect. VIII. Coincidental figures on the part where the maximum distribution rate was shown and the part where the maximum average dimension of the body length of the trophozoite were considered as indicating the optimum site of the parasite.
parasitology-protozoology-Giardia muris ; mouse ; intestine ; habitat ; animal