Blepharisma undulans. 339 



The relative opsonizing power of various sera was found to be 

 as follows: 



Rabbit No. 



Route of Immunization. 





320 



I ntra venous 



O tA ft Of 

 2 ,'q tO O /o 



329 



Intravenous 





330 



Intratracheal 



10% tO 20% 



33i 



Intratracheal 





332 



Subcutaneous 



2% tO 4% 



333 



Subcutaneous 





334 



Intrapleural 



10% tO 20% 



335 



Intrapleural 





336 



Normal (control) 



below 1% 



337 



Normal (control) 





In the test for protection three series of mice received intra- 

 peritoneally 1/2 c.c. of the respective sera each. Immediately fol- 

 lowing the serum mice of respective series received intraperito- 

 neally virulent culture in the amount representing from 12,500 to 

 50,000 M.L.D. 



Route of Immunization. 



Number of M.L.D. of Pneumococcus. 



12,500 



25,000 



50,000 





living 



living 



-f 24 hrs. 





living 



living 



living 





+ 24 hrs. 



+ 24 hrs. 



+ 24 hrs. 





living 



living 



living 





+ 24 hrs. 



+ 24 hrs. 



+ 24 hrs. 



161 (1908) 



Racial variations in Blepharisma undulans. 



By LORANDE LOSS WOODRUFF and HOPE SPENCER. 



[From the Osborn Zoological Laboratory, Yale University, New 



Haven, Conn.] 



Studies on Blepharisma undulans and Blepharisma lateritia 

 Stein, have emphasized the impossibility or great difficulty of 

 observing the micronuclei, and also the inevitable death of ex- 

 conjugants without dividing. Thus Butschli 1 was unable to iden- 

 tify micronuclei in vegetative specimens of B. lateritia though he 

 found them in conjugants. Exconjugants invariably died. Cal- 

 kins 2 did not find micronuclei in non-dividing B. undulans, but 



1 Biitschli, Abhandl. d. Senckenb. naturf. Gesellsch. Frankfurt a/M., 1876, Bd. x. 

 8 Calkins, Journ. Morph., 1912, xxiii. 



