232 < ME. S. LE M. MOORE'S STUDIES 



necessary to give in detail, as was my first intention, all the expe- 

 riments upon the callus of the first-mentioned tubes, made pri- 

 marily with the object of finding out whether it will give proteid 

 reactions and will peptonize. The results obtained may thus be 

 epitomized : 



1. The callus rapidly dissolves on warming sections in Millon's 

 fluid ; and does so without showing any tendency to become red. 



2. It is soluble in boiling hydric nitrate ; hence the xantho- 

 proteic test does not succeed. 



3. On running in caustic potash after sections have lain some 



time in copper sulphate, the callus swells up, but does not turu 

 blue or pink. , 



4. After a good soaking in syrup, hydric sulphate swells the 

 callus so that it is almost invisible, but it never assumes the 

 slightest tint of pink. 



5. After many experiments with a peptic fluid, allowed to 

 act as long as 86 hours, the callus underwent not the least 

 change in form and general appearance ; and it now reacted 

 quite normally with picric blue and corallin soda. 



G. The same result followed every attempt to dissolve the 

 callus in a pancreatic fluid (Fairchild's pancreatic extract). 



On the other hand, the substance closing the sieves of the 

 inner tubes behaves thus : 



1. It stains yellow with picric blue. 



2. It takes a temporary pink with corallin soda. 



3. In hydric sulphate there is no appreciable swelling up, 

 nor in caustic potash. 



4. Iodine stains it brown. 



5. It is unacted on by carmine. 



6. It gives good proteid reactions. 



7. On many occasions it dissolved in a peptic as well as in 

 a pancreatic fluid. 



This substance therefore greatly resembles the substance of 

 Ballia stoppers; at the same time it is quite different from 

 callus in its reactions and chemical constitution, although the 

 same function of obliterating the sieves is performed by both. I 

 propose to call it " paracallus," the term callus being an unsuit- 

 able class-name to include both a proteid and a non-proteid 

 substance. 



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