PLATE VII. 



Figs. 1-11.— DINAMCEBA MIRABILIS. 



Fig. 1. Individual containing, besides a number of food-balls, a large Closterium which had been 

 swallowed when one-half of the cell after division was yet in the soft condition and allowed of being 

 doubled on the more consistent portion. The large conspicuous globule situated posteriorly remained 

 for a longtime unchanged but was finally discharged. From a cranberry -bog of Atco, N. J., September 

 21, 1877. 250 diameters. 



Fig. 2. The same individual as seen the following morning, September 22. 333 diameters. The 

 spicules or minute eils of the surface had everywhere disappeared. The Closterium had been dis- 

 charged, and the interior was occupied with a multitude of clear globules. The pseudopods were long 

 and pointed and were incessantly changing. The five pseudopods at the fore end, from the short knob 

 to the two blunt ones on its right and the two longer pointed ones on its left, illustrate the mode of 

 production and gradual extension of these temporary organs. 



Fig. 3. An individual devoid of spicules, moving from right to left, the interior filled with 

 numerous segments of Didymoprium enclosed in drops of liquid. From Absecom pond, New Jersey, 

 June, 1876. 250 diameters. 



Fig. 4. A small individual of the usual form and appearance. It contains a few segments of 

 Didymoprium, the ordinary food; and at the posterior part a number cf small contractile vesicles are 

 seen. Atco, N. J., September, 1877. 250 diameters. 



Figs. 5-7. Three views of an individual, as it appeared at successive periods during 30 hours. 

 The fore part of the body bristled with pointed pseudopods, while the posterior part was thickly papil- 

 late, but no part of the surface exhibited spicules. In fig. 6, the nucleus is concealed from view; in 

 fig. 7, the green desmid of the former views has become brown. Absecom Pond, New Jersey, November 

 4th to 6th, 1874. 300+. 



Fig. 8. Individual like the preceding, as observed swimming. From the same gathering. Sep- 

 tember, 1874. 530+. 



Fig. 9. An individual which remained nearly motionless and without pseudopods. The interior 

 occupied with abundance of food-balls and largo clear globules, but no distinct contractile vesicle nor 

 nucleus observed. The posterior semicircumference of the body finely ciliate, but the anterior smooth. 

 Atco, N. J., September, 1877. 250+. 



Fig. 10. Individual, from the same gathering, containing comparatively little food and exhibiting 

 a distinct granular nucleus. 



Fig. 11. Pseudopod of an individual, from the same gathering, observed October, 1877. The 

 animal of the usual size, and well filled with food, had the surface of the body finely ciliate, but in 

 addition it and the pseudopods appeared to be covered by minute adherent granules as represented in 

 the figure. 500 diameters. 



Figs. 12-19 illustrate the series of changes observed in the swallowing and digestion of an 

 Amwba verrucosa by an A. proteus. From Bristol marsh, Pennsylvania, August 27, 1876. 500 diameters. 

 Fig. 12. Amoeba verrucosa, comparatively quiescent, with central contractile vesicle. 



Figs. 13-19. Successive changes in shape and relative position of A. proteus during the act of 

 swallowiug and digesting the former. Fig. 13. A. proteus approaching the J. verrucosa, with anterior 

 short diverging pseudopods. Fig. 14. The A. proteus embracing closely the A. verrucosa by a pair of 

 digitate pseudopods, the points of contact of which being marked by the left-hand arrow. Fig. 15. 

 The A. verrucosa swallowed and forming a large sphere within the A. proteus. Fig. 16. The A. ver- 

 rucosa, within the latter, has assumed an oval form, and is contained within a vacuole. The ceutral 

 contractilo vesicle, which until now had remained persistent, has become less distinct. Fig. 17. The A. 

 verrucosa has assumed a pyrifonn shape within a large elliptical vacuole, and its contractile vesicle has 

 disappeared. Fig. 18. The A. proteus in the act of discharging a diatom, -while the A. verrucosa has 

 become doubled on itself. Fig. 19. The remains of the A. verrucosa, seen as five granular balls within 

 the A. proteus. Later these balls disappeared, and their material appeared to be diffused among the 

 granular contents of the A. proteus. 



