196 Proceedings of the Royal Physical Society. 
complete bipyramids of the same series. The non-diatom feeder contained 
medium and small crystals of this latter form. 
- Later in my study, the locality classification gave way completely— 
but I was in a position to differentiate between the two amcebe formerly 
passing indiscriminately under one name. Whatever their locality, I had 
found that the diatom feeder reproduces by mitotic division of its 
nucleus with subsequent division of its protoplasm, as also by reproductive — 
cysts; that the non-diatom feeder also multiplies by division, but I had not 
observed this in such a way as to be able to state whether the nucleus 
divided by mitotis or amitosis. 
I wish to draw special attention to the amceba upon which I worked so 
persistently (the diatom feeder), because I have called it A. proteus Pallas, 
which name will be shown to be correct and should remain with this type 
if ever we can definitely prove that these amcebe are not all one species. 
During these years the multinucleate type of A. proteus had of course 
presented itself, but, with the non-diatom feeder, had been more or less 
discarded in the study of the diatom feeder. 
At the end of this time I reverted to my original idea of one species, 
but now with strong reasons for preference for that which I had formerly 
taken for granted. It was, therefore, in July 1914, after a consultation with 
Mr C. H. Martin,! sometime Protozoologist at the University of Glasgow, 
and a great student of amcebe, that I re-arranged the grouping of the amcebze 
and designated the three types A. proteus X, A. proteus Y, and A. proteus Z, 
being with him practically convinced that the whole history is that of one 
amceba, complicated and involved no doubt, as recognised by all, but still 
one species only. 
The suggested arrangement would, therefore, be :— 
A, proteus X (Fig. 1). The amcba spoken of earlier as the “ Lapworth ” 
type; the diatom feeder; the amceba which I designate as A. proteus Pallas, 
in my preceding papers”; excellently figured by Leidy* and by Griiber* as 
A, proteus; by Cash and Hopkinson® as A. proteus Pallas; the amceba 
renamed by Scheeffer® A. debia (or dubia) under the group of “raptorial 
1 The noble death of Lieut. Martin, in his country’s cause, has left me without his 
further help and kind encouragement, but in writing up the notes embodied in this paper 
I am fulfilling his last wish expressed to me before going to the front, and at the same time 
recording my own thanks which are so justly due to him. 
2 Carter, loc. cit. 
3 Leidy, loc. cit. (pl. 1 fig. 2, pl. 2 fig. 4). 
* Griiber, Zert. ftir wiss. Zool., Bd. xli., 1885, “Studien uber Amében.” 
® Cash and Hopkinson, “British Freshwater Rhizopods,” London, Roy. Society,vol.i., 1905. 
6 Scheeffer, loc. cit. 
