91 



becomes encysted in the colon, so that usually only the encysted 

 stage IS found in the feces; but in case of increased peristalsis and 

 diarrhea the organisms have not time to encyst, so that the free 

 stages are observed in the stools. As the parasites become cool 

 motion decreases; when raised to high temperature, as 50° C, 

 motion becomes slow, and the organisms die at 62° C. or below 0° c! 

 Pathogenicity.— Opinion differs as to the pathogenicity of this 

 organism. Perroncito (lfi02b) reports it as causing a fatal disease 

 in rabbits. Braun (1908) is inclined to consider it harmless. From 



Fig. 14. — An epithelial cell with parasitic Lamblia. 

 Greatly enlarged. (After Grassi & SchewiakofE, 

 1888, pi. 15, flg. 6.) 



Fig. 15.— An individual in the act of joining an 

 epithelial cell. (After Grassi & Schewiakoff, 

 1888, pi. 15, flg. 7.) 



conversation with Doctor Hemmeter, we are persuaded that in his 

 case in a child in Baltimore the parasite was not without effect. 

 Possibly the question as to its pathogenicity is a relative one in 

 that light infections may produce no recognizable disturbance, while 

 heavy infections may produce recognizable effects. Doctor Hemme- 

 ter's original letter regarding his case contained the following notes: 



Patient, male, white child, 3 years old, born in Maryland. Had recurrent attacks 

 of colitis all its life; three acute attacks within the last three weeks, accompanied by 

 fever, distended abdomen, sensitive, etc. Stools have always been like putty, con- 

 taining large amount of mucus, and some blood streaks; fever lasting three days, no 

 pronounced diarrhea, 2 to 3 passages per day; intervals between attacks variable, 

 stools at such times like putty, also with mucus. 



