Lazelle B. Stnrdevant 



i 



illation. Aside from its convenience, it can easily be cleaned, and 

 it replaces the fibrous contents of the intestine so that the womis 

 need but little washing to make them clean. 



In one of the thirteen rats infected with trypanosomes in the 

 blood the bladder harbored two nematodes ; in another three. 

 Nearly all of the thirteen were kept alive for several days (3-5), 

 but it is hardly possible that infection may have taken place in 

 this laboratory. Ectoparasites were absent in most cases. Of 

 those examined for sex, eight were male and two were female. 

 Three cases showed small cysts in the liver. Ten harbored ces- 

 todes varying in number from i to 93 ; all were caught during 

 November, December, and early January. All but two were from 

 oiie restaurant, the other two being captured but ten or twenty 

 yards distant from this. One rat was infected with six nematodes 

 in the stomach. Only one was full grown, while eight were half 

 grown or smaller. 



The five rats which harbored nematodes in the small intestines 

 were of all sizes, came from a variety of places, and all harbored 

 cestodes, from i to 100 in each case. They were all caught dur- 

 ing September, October, and November. Three were males and 

 one female. One had two nematodes in the stomach. Ectopara- 

 sites were present in one case. No case was infected with try- 

 panosomes or with nematodes in the bladder. Hymcnolcpis mii- 

 rina was found in one case. Twenty-one rats (20.4 per cent) 

 harbored nematodes in the bladder. Sixteen of these were full 

 grown, but one was less than two-thirds grown. They came from 

 a great variety of places. Sixteen contained cestodes in the small 

 intestine, from i to 50 in number. In six, small cysts were noted 

 in the liver. Eight were males and four were females. Ecto- 

 parasites were observed in a third of the cases. Most of them 

 were killed on the day captured. Two cases showed trypano- 

 somes in the blood. In twenty cases, sixty-six nematodes were 

 found, an average infection of three worms, but varying from i 

 to 17. In the twenty-first case the nematodes were too numerous 

 and too badly tangled to be accurately counted. One worm 

 among these was red. but lost its color after lying in alcohol for 

 a time. 



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