200 



LORANDE LOSS WOODRUFF AND HOPE SPENCER 



of a large number of such captures, however, justifies, we beheve, 

 the following general description. 



When the prey fails to remain in contact with the oral region, 

 the Spathidium immediately gives a series of avoiding reac- 

 tions, which, unlike those that occur when the prey remains in 

 contact, tend to increase in extent so that the organism not only 

 remains in the general region in which the attack occurred, but 



Figs. 1 to 8. Food-taking by a single specimen of Spathidium spathula. 1. 

 Animal when first observed. Contains one food vacuole enclosing a Colpidium 

 (1). The contractile vacuole is shown at the posterior end of the Spathidium 

 in all the figures. 2. Seizing a second (2) Colpidium. 3. Second Colpidium 

 enclosed in food vacuole. 4. Third Colpidium being engulfed. 5. Third Colpid- 

 ium in food vacuole. 6. Seizure of fourth Colpidium. 7. Fourth Colpidium 

 within vacuole; food vacuole with first Colpidium no longer discernible. S. En- 

 gulfing of fifth Colpidium. Observations, extending over about an hour, and 

 drawings by Miss J. Elizabeth Lovett, artist to the Osborn Zoological Laboratory. 



