Some Observations on Amoeba proteus. oy 
amebas.’ Its nucleus is shown in its typical condition by Griiber. The 
crystals contained in the plasma of this amceba are large. 
A. proteus Y (Fig. 2). <A series of amcebse which show a gradation of 
characteristics from X to Z, so gradual that classification becomes at times 
almost impossible. It is a non-diatom feeder; the amceba spoken of as 
“Sutton” type in the beginning of this paper. Members of this series are 
most commonly figured as A. proteus in text-books and elsewhere, whatever 
form may be described in the text itself—eyg. Doflein in his Lehrbuch der 
Protozoenkunde, pp. 11 and 570, under the title of A. proteus Pallas; 
Cash and Hopkinson as A. proteus Pallas, var. granulosa; Scheffer breaks 
the series up into two species, A. proteus Pallas emend. Leidy, and 
A, discoides Scheffer. In the excellent figures by Leidy the individuals 
shown in plate ii. figs. 1 and 2 are apparently nearing the 7 end of the 
series. 
A. proteus Z. The multinucleate form of A. proteus, practically similar 
in all respects to A. protews Y with the exception of the number of its 
nuclei. It also is a non-diatom feeder. 
POINTS OF DIFFERENCE. 
In 1879 Leidy summarised the history of this amceba and concluded, 
“TI therefore suggest that the name Amwba proteus should be employed 
for the common large amceba,' recognisable as the Proteus of Rosel and the 
Ameba princeps of Ehrenberg; otherwise, according to the strict laws of 
scientific nomenclature it should be Ameba chaos.” 
From this it would seem that Leidy included in this species proteus— 
all the amcebee of the proteus type as figured by him—thus including the 
multinucleate type. 
I would certainly retain this name Amwba proteus, but with some such 
distinctions as those above mentioned to simplify matters as to the 
appearance, condition, or phase of life of the ameceba at the time of 
observation, until the whole life-cycle, or life-cycles, if such there be, can 
be written. 
The constitution of the individuals of the proteus group or series XY, Y, Z 
is similar; a mobile mass of protoplasm, capable of pushing out pseudopodia 
from any portion of its mass; no pellicle, and apparently no differentiation 
of ectoplasm and endoplasm, which is to say that these latter are convertible 
' It would be preferable to say large amceebw—since Ehrenberg himself declared that 
der kleine Proteus, Rosel’s amoeba, was not like his A. princeps of Berlin, and he must have 
seen Rosel’s illustrations, 
