504 



Dr. H. L. Duke. 



[Sept. 2, 



either almost in contact with the posterior end, or at varying distances from 

 this extremity up to 4'5 /x. 



Nucleus : Situated near the middle of the body. 



The following Table I gives the measurements from four experimental 

 animals. 100 examples were drawn from each experiment : — 



Table I * 



Expt. 



18/*. 



19/*. 



20/*. 



21/*. 



22/*. 



23/t. 



24/*. 



25/*. 



26/*. 27/*.|28/*. 



29 M . 30 m . 31/*. 



32/*. 33/*. 34 /*.| Average. 



Eat 780 



Eat 696 



Monkey 646 

 Dog 671 



1 



1 



6 

 1 

 5 

 6 



7 

 3 

 4 

 6 



11 



4 

 8 

 12 



11 

 7 

 8 



11 



7 

 9 

 6 

 11 



el 7 



5 | 5 

 11 ! 18 

 17 12 



10 8 

 15 15 

 13 16 



15 1 8 



8 

 9 

 2 

 2 



10 



4 



6 

 6 

 2 



3 

 5 



2 1 



25 1 

 27 -0 

 25 -5 

 24 -4 



Totals 1 



1 



18 



20 35 



37 | 33 



39 



42 



53 41 



21 



34 



14 



8 



2 1 





Percentages .. 



0-2 0-2 



4-5 



5 



8-7 



9-2 



8-2 



9-7 



10-5 



13-2 10-2 



... 



8-5 



3-5 



2 



-5 | -2 





* In the table of measurements of the antelope trypanosomes as printed in my paper earlier in this volume (p. 166), 

 two numbers are omitted, viz., in column 18/* on line (2) 511, monkey, the figure 1 is omitted, and in the line, of 

 totals the figure 7 is omitted. 



The fly experiments may now be briefly summarised. On no occasion was 

 a successful transmission obtained and no flagellates were found in the flies 

 employed, either in proboscis or gut : — 



Table II. 



Expt. 

 No. 





Number of flies. 



Duration 

 of 





Period on infected animal. 



1st 

 day. 



30th 



Dis- 

 sected. 



Containing 

 flagellates. 



experi- 

 (days). 



Eesult. 



680 

 681 

 683 

 684 

 687 



698 



Mar. 27—30 on Monkey 676 

 „ 28—30 „ 676 

 „ 31— Apr. 4 on Dog 671 



Apr. 1— 6 „ 671 

 2— 6 „ 671 

 „ 8—15 „ 671 

 „ 10—15 on Monkey 676 



48 

 42 

 82 

 47 

 62 

 79 

 73 



35 

 29 

 56 

 26 

 43 

 47 

 40 



48 

 42 

 82 

 47 

 62 

 79 

 73 





 

 

 

 

 

 



33 

 32 

 30 

 29 

 52 

 45 

 41 







Totals 



433 



276 



433 

























Animals Susceptible to this Trypanosome. — In the following table those 

 experiments marked * were performed by Mr. Montgomery, and I wish to 

 express my indebtedness to him for the permission to quote them. It will be 



