1919] 



Boeck: Studies on Giardia Microti 



93 



this rat was infected and then became free, showed that it was capable 

 of throwing off the infection. There was no reinfection as can be seen 

 from the records, which run negative for thirteen days. 



Rat 4. The degree of infection was very light in this animal for 

 the greatest number of cysts found in the faeces was four on November 

 10 and 11. There were two periods when cysts were found in the 



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:: 



\ 



ZES 



\ 



\ 



23 26 27 2S 20 30 ,'il 12 3 4 



9 10 11 12 13 14 15 16 17 IS 19 20 21 



Eat 4 

 Fig. 4 



/\ 



V 



L 



25 26 27 28 29 30 31 1 2 3 4 5 6 7 S 9 10 11 12 13 14 15 16 17 IS 19 20 21 



Eat 5 



Fig. 5 



faeces. The first period was two days in length and only one cyst 

 was found on each day. Then came an interim of depression of six 

 days in which the examinations revealed no cysts. The mode of the 

 second period of cysts in the faeces came on November 10, and the 

 period ended November 19. The interval between the two modes is 

 seven days. 



Rat 5. The first period of cysts in the faeces, October 30 to Novem- 

 ber 1, results in a portion of the graph sharply set aside from the 



