43. 



eeroaria of gohinos tome reyrlutuau The evidence is frr ra two 

 sour aes ; first, th-it in some oases the number of cyst* 

 exceed four hundi*'?d. while three hundred *nci two hundred 

 cy^ts in the grume snail ia not unocviBion. That four hundred 

 or three hundred cerca i^ oould find tiieir 'way into a 

 singlx? snail from the open water seems impossible* ?ven 

 for Wo hundred oeroaria-* to so snt^r seems extremely 

 improbable, I ohnuld say that fifty e-?roari*te so finding 

 entrance to one an -Ail TOuld be unlikely and in fact in the 

 majority of aw*p less than fifty cyigtn ar** present* The 

 ^'xnd evidence ia more dired^, aince a Btill further shorten 

 i.ng of the r>roce*fl cf rnioystraent has been aaen aiaiiy times* 

 v/hen this 9>u:rlenin^ occurs the oerc^rime encyst within the 

 redi e without rt ver ia*iKing thru thebirUi pore. Almcnt by 

 arci;nt fifty*i^ht rediaf were found ^ith yts inside, 

 since in the great majority cf snails examined no special 

 attempt -was made to see how many oould be so obtained* Of 

 these fifty-eight oystB inside redine, twenty-six occurred 

 singly (fig. 32), six r*iiae had two oysts each (fig. 



four contained three oysts each (fig. 34) and two had four 

 oyets each inside (fig. 36)* !Ihat oeroariae ocming from 

 the open water could penetrate the redid e said there encyst, 

 two, three, or four in number is entirely impossible, in 

 fact, that one ceroaria should penetrate a redia anu encyst 

 is quite improbable. These rediae containing oyt were 

 found in thirteen different snails. The rediae containing 

 these cysts were of different shapes nnd sifces, being 

 large, of normal shape or constricted t one or no re 

 They also differed much in color and activity. The majority 



