88 



FRESH WATER EHIZOPODS OF NORTH AMERICA. 



Some hours later, on examining the same Dinamoeba, which had been 

 preserved in the animalcula-cage, it presented the appearance represented 

 in fig. 6, pi. VI. It was oval in shape, 0.272 mm. long by 0.16 mm. broad, 

 and sitting, as it were, on a Didymoprium. From the head projected a num- 

 ber of pseudopods. The posterior extremity clasped the alga by means of 

 a transverse cylindrical process of greater length than the breadth of the 

 body. The ends of the process on each side were extensions of the ectosarc 

 fringed with papillae. The cylinder embraced the alga so tightly as to 

 contract its gelatinoid sheath close to its green cellular axis 



While watching the Dinamoeba, without any suspicion of what was to 

 follow, and with the impression that the animal was holding a resting 

 position, as seen in the woodcut 13, the Didymoprium suddenly broke 

 within its clasp, as represented in the following woodcut 1 4. 



ifiitiiH~HM i iPiliiii i i ' i n r i^rtiS^QtsA ' " : '.. i l& o>. / ■'---' 



j 3 " : . ,sSSS ^~~Z~C^. 



W 



Kit 



if 



Successive changes observed in Dinamoeba mirabilis while in the act of swallowing a fila- 

 ment of the alga Didymoprium. 



The animal subsequently passed through the successive changes 

 seen in cuts 15-21. The Dinamoeba gradually shortened, the pseudo- 

 pods in front diminished to two, the two portions of the alga Avere 

 made to approach each other, and the right side of the body projected 

 in a nipple-like prominence, from which there were suddenly discharged 

 upward of twenty cells of Bambusina (If)). These were probably 

 derived from the filament swallowed, as previously described. The cells 

 were nearly all separated, and contained only the shriveled remains of the 

 endochrome. 



The Dinamoeba again became elongated, all pseudopods disappeared, 



