310 JOHN W. SCOTT. 



amount of evagination over that when it is used alone (lot n). 

 Lot 5 shows that artificial gastric juice is harmful to the cysticerci' 

 for it tends to digest them and undoubtedly interferes with 

 evagination (cf. also lot 9). This last effect is due to the acid. 

 Artificial pancreatic juice as used in lot 8 is more effective than 

 either of its elements used separately (cf. lots I, 6, and 7). But 

 we find that artificial pancreatic juice produces its best results 

 when preceded by treatment with artificial gastric juice. In lot 

 9 this treatment gave 100 per cent. An almost equally good 

 result was obtained in lot 10 when treatment with an acid 

 (hydrochloric) was followed by an alkali (sodium carbonate). 



This experiment or parts of it were repeated several times, 

 but the results were invariably similar in character. Other 

 experiments like these were tried upon the cysticerci of T. 

 serialis. The results were so much like those described that 

 there is no need to give details here. The cysticerci of this form 

 are more apt to be digested by the gastric juice, probably due 

 to their smaller size. While much remains to be done in this 

 connection, it is believed that one may safely draw the following 

 general conclusions: 



1. Treatment with artificial gastric juice followed by immersion 

 in artificial pancreatic juice furnishes a ready and efficient means 

 of producing the evagination of cysticerci of T. serrata. This 

 is an easy method of obtaining material for preservation and for 

 the study of the living parasites. It is best to use the gastric 

 juice in a diluted form if one wishes to preserve the bladders 

 intact. 



2. In producing evagination the most important factors in 

 artificial pancreatic juice are the alkali, sodium carbonate, and 

 the extract of pancreatin. But to obtain the best reation to these 

 stimuli previous treatment with hydrochloric acid is required. 



3. Treatment with an acid followed by an alkali (lot 10) gives 

 rather better results than treatment with pepsin followed by 

 pancreatin .(lot n). Hence the sodium carbonate appears to 

 be a more important factor than pancreatin in producing evagi- 

 nation. 



4. The cysticerci are not digested in the stomach of the dog 

 because they do not evaginate in a harmful acid medium. The 



