FORMATION OF FOOD-( I I'- I\ AMcKBA. 



237 



the protuberance formed by this local expansion becomes firmly 

 attached to the substratum and the enclosed area arches upward 

 causing much of the endoplasm between tin- upper and lower 

 surface to recede: thus forming a spoon- or cup-like concavity. 

 The marginal -urtace of this concavity draws slowly together 

 troin all direction- reducing the aperture of the concavity until it 

 ntirrly do-cd. A vesicle is thus fornu-d not unlike tin- 





Ku.. i. 1 \M> /<. l-'n-c hand sketch of the pscudopod of an Amoeba during the 

 formation ot a inml-ciip. 



Ku.. j. A ^imil.ir k-u-li ..I a I l-cup which involve-; alumst the rntin- .1 maeba. 



I-' n.. ,\. Aix'tln-i typi-i-i food-cup f<wmation in which two accessory pseudopoda 



ati-i- ami a'lvaiiif i nii-<-i. utivrly through positinii^ indicated l>y a, b, c, d, e inl- 

 l..\\r.l liy .in i.vrrau liini; -lu-rt -I i i toplasm indicated by a 1 , b 1 . <:'. </'. f 1 . 



FIG. 4. In thi< t\-]' oi ip formation tin- two i-up- t'oriin-d are connected 



by a strand of protoplasm. 



