142 RESEARCH IN PROTOZOOLOGY 



both ANURA and urodela. Studies of the host-parasite distribu- 

 tion of this species should be especially interesting since it seems 

 to have established itself in both warm-blooded and cold-blooded 

 hosts. 



Giardia nmris (Grassi, 1879) Bensen (1908) has been reported 

 for a number of species of rats and mice but a wide distribution 

 among other hosts has not been indicated. A second species of 

 Giardia has been noted by Boeck (1919), Simon (1922), Lavier 

 (1924), Nieschulz and Krijgsman (1925) and Hegner (1927c) 

 and has recently been shown by Potter (1928) to be morphologi- 

 cally identical with the Giardia of man. Hegner (1927c) has dem- 

 onstrated that the Giardia of man can excyst and colonize itself 

 in rats. The rat therefore does harbor the Giardia of man, but to 

 what extent is not known. It is desirable to determine if other 

 hosts may harbor the species found in man, or if man may not 

 sometimes harbor species other than G. lamhlia. 



