GENUS AMCEBA— AMCEBA PEOTEUS. 47 



successively became detached to be carried along with the rest of the con- 

 tents. As the posterior part of the body became exhausted of its axial 

 contents, it contracted, shriveled, and kept up continuously the mulberry- 

 like aspect of this region, as seen in the figure. 



Mostly in the contraction of the posterior part of the body of Amoeba, 

 or of its pseudopods, as they exhaust themselves through the flux of their 

 endosarc, the ectosarc closes up more or less evenly with the latter. In the 

 Amoeba under consideration, in similar contraction of parts, the ectosarc 

 appeared to be slower in its closing-up, so that they became more or less 

 shriveled processes in their shrinkage. 



Another large individual, in general form like the letter Y, measured 

 0.64 mm. long-, with cne of the divergent arms 0.4 mm. long by 0.04 

 mm. thick. The two' arms continued to diverge until they divided the 

 main stalk of the body, and became extended together, in nearly the 

 same line, so as to measure two millimetres in length. I supposed the two 

 limbs were about to divide, but subsequently one reversed the direction 

 of its motion and flowed into the other, and the animal then assumed a 

 palmate appearance. 



Another specimen, when first observed, covered a space in both direc- 

 tions measuring about 0.6 mm. It appeared to be in the act of division, 

 consisting of two portions connected by an isthmus; but subsequently one 

 portion flowed into the other, while this extended three divergent pseudo- 

 pods. The contracted pseudopods of the former portion shriveled into 

 beaded cords, and then inelted-away in the progressing body-mass. 



This specimen, retained under observation during two days, with 

 the idea that it was about to divide, finally appeared as a quiescent oval 

 ball 0.46 by O.o8 mm., closely covered with small round pseudopods of 

 clear ectosarc, looking like dew-drops, measuring 0.012 to 0.016 mm., and 

 occasionally containing a few granules or a minute crystal. 



The largest individual observed among the Amoebae, from Woodstown 

 pond, extended into two arms from a posterior mulberry-like mass, which 

 measured 0.2 by 0.16 mm., with one arm 0.8 mm. long by 0.08 mm. thick, 

 and the other arm 0.6 mm. long by 0.06 mm. thick. The contractile vesicle 

 occupying the interior of the mulberry-like end of the body was 0.06 mm. 

 diameter. The crystals of the endosarc, apparently octahedral in form, 

 appeared to reach 0.075 mm by 0.0375 mm. 



