How long an encysted agarao <* i ^ to m* may live in a living 

 snail hag ilso nev*r been d termiried* Sinae oeroariae 

 are not produoed during t inter months, and sinoe cysts 

 are found thruout tne year, it is obvious that they live 

 for -it 1 ' ist four months. Doubtless they exiat fr a 

 year '*nd perhaps aever-il years in the tissues of the snail 

 before deterioration and death* By raising eggs of 



in aqunria and by placing '^itli these 



youn : : onails the sro.iria< of 'fchinogtotaa ryolutum^ thu 

 duration nf t)i ayat aould be detsriain*sd by examination 

 of the snails froia month to nonth. 



The following tabl^ give* an analysis of the various 



stages of <chino8tctaa rgvolutuia found in the four hundred 



size of 

 of va ri o us /Hiy 8 Li a Occidentfiilis taJ'en frciai Stew 



Golden G*t Par^, Ban 



Mo ther*r*dia&* ............................... 13 



J)aughtrr6dia! and caro?ria** ..*.......... 234 



Encysted ag^riruf) die uuans or oysts* *.*...... 262 



Cysts only... ........ . ..... .................. 95 



Cysts within re<ii >**.......,............... 15 



Uninfentad snails. . . ........ .............. ....;;,; 



These snails ^ere exaroined during every month of the 

 except July. The cynt ami dau^hter-redia stages 

 were found during every ^Bon&h but the mother-redia stage 

 found only in the months of i% member, January and 



ary* oinoe the niother-redia stage waa net Vnown or 

 even suspeoted until December 1918, it is obvious that 

 more t .an thirteen snails nrre ^o infected. Also, ninoe 

 as stated, no effort was nade tc se^ if all the snails 



