91 2. 



Plate C\'I. 







Pu'.. 114. — Section of th\Toid of dog 20 used iis control for dogs 22 

 nnd 22. but. like control dog 21. boiled before drinking. X160. 



I \ 



16 and 17. Received the same water as dogs lo. 17 



Fig 115. — Dog 22. Section of enlarised thyroid. Well developed hyperplasia after drinking water five months with 

 suspended scrapings from infected fish troughs. The same experiment and result as dog 16- figure 111. and dog 17, 

 figure 112. X160. 



