54 Proceedings of the Royal Physical Society. 
X.—Note on a case of Mitotic Division in Amoeba proteus Pall. 
By Lucy A. Carter, 8.N.D., B.Sc. Research Student, Glasgow 
University. 
(MS. received 21st March 1913. Read 24th March 1913.) 
INTRODUCTION. 
Ir has long been a matter of much regret that the complete life-history 
of Amoeba proteus has not been worked out during the many years it has 
held so important a position in the laboratory work of students of 
zoology. Isolated experiments have been performed, and short papers 
have been written upon isolated facts in the life-cycle of forms which are 
acknowledged by their authors to be not certainly A. proteus. This leads 
to confusion, and the extent of this confusion can only be realised by a 
student who takes up the subject with an earnest desire to follow the 
consecutive stages in the life-history of this organism. 
Stole’ has published papers upon the origin of the multinucleate forms 
of A. protews, which entailed the noting of over 250 divisions, but gives no 
particulars of the cytology of it. Calkins? wrote upon specimens prepared 
by his class students, finding a case of “full mitosis,” which, it is to be 
regretted, in no way agrees with what is put forward in this note, though 
one is tempted to think, with Calkins himself, that sections might have 
made things clearer, especially in his Taf. 3, fig. 14. The only worker 
who has described in detail and figured mitotic division in A. proteus is 
Awerinzew.*® In his preliminary note in 1904 he compares the division 
with that described by Schaudinn* for A. dinucleata, with which, again, 
the following description cannot be said to agree in all respects. 
The great variety of opinions, not merely as to facts of the life- 
history only, but even as to the appearance of 4. proteus, indicates the 
need for still further investigation of this much-investigated type. The 
‘following note refers to one of the results of an extended research upon 
A. proteus which has been going on for nearly three years, with the 
assistance of the Carnegie Trust. The particular specimen referred to here 
answers well in general appearance to the description given by Leidy, 
and figured by him in his plates I. and IIL, with the exception of fig. 7, 
L Archiv, fiir Entwicklungemech, der Organism, xxi, Band, 1 Heft. 1906, p, 111. 
2 Archiv. ftir Protistenk., Bd. 5, p. 1. 
3 Zool. Anz., Bd. xxvii., Nr 12/13 1904, p. 399. 
4“ Uber die Teilung von A. binucleata Grub.” Sitz-Ber., Ges. naturf. Freunde., Berlin, 
1895, pp. 130-141. 
