Amitosis in the Ovarv of Protenor belfragei and a Study of the Chromatin Nucleolus. 201 
is shown by the amount of attention this method of division has received 
front earlier investigators. 
Walker (1906) States that “amitosis occurs as one of the earliest 
known phenomenon in the production of spermatozoa in some animals 
if not in all” (p. 56). 
In Flemming’s (1892) historical sketch of amitosis he gives a list 
of the many investigators who have demonstrated direct division in the 
following cells, lymph cells, epithelial cells, gland cells, connective tissue 
cells, muscle cells, and gerat cells, botli in spermatogenesis and in oögenesis. 
Wheeler (1889) demonstrated amitosis in the follicle cells of Blatta 
germanica and described it as follows: “In eggs taken front the ovaries 
just before maturity, when the epithelial is firmly attached to the under- 
lying chorion almost all of the nuclei will be found rapidly dividing . . . 
but no trace of an achromatic spindle or of a regulär arrangement of 
the nuclear filament, so characteristic of karyokinesis could be observed. 
I therefore conclude that we have here a case of akinesis or direct divi- 
sion. This conclusion is further strengthened by the observation that 
the nucleolus divides first . . . Moreover, the two daughter nuclei are 
frequently very unequal in size” p. 296 — 297. 
For a decade or more mitosis has gained in popularity at the expense 
of amitosis, the ntore obvious and attractive features of ntitosis offering 
perhaps a prontise of ntore fruitful results to the investigator, whereas 
the obscure and doubtful features of amitosis, added to the populär 
Suggestion made by Ziegler and Vom Rath that it is associated witlt 
degeneration of the cell, have tended to increase the difficulties of at- 
tempting to demonstrate that amitosis may play as important a role 
in development as mitosis. 
Among the exceptions to this attitude towards amitosis are Prof. 
Child’s carefid work on Nematodes (1904 — 1910); Jörgensen’s (1908) 
Study of the Oögenesis of Nephelis, Jordan’s (1908) Spermatogenesis of 
Opiopus Mayeri, Glaser's (1908) Study of the Endoderm of Fasiolaria 
iulipa vardistans, Patterson (1908) on the Pigeon’s Egg and Moroff's 
(1909) Oogenetische Studien. I. Copepoden. To these may be added, 
Knoche’s (1910) important observations on the insect ovary, Maximow 
(1908) on the embryonic tissues of the rabbit and Nowikoff’s (1910) 
demonstration of amitosis in the bone and sinew of the young mouse. 
Of the latter he says: »Die amitotischen Teilungsfiguren sind in solchen 
jungen Sehnen sehr zahlreich, so daß man auf einem und demselben Quer- 
schnitt alle möglichen Zerschnürungsstadien auffinden kann (Textfig. 2). 
Die Karyokinesen trifft man dagegen äußerst selten. «... »In den meisten, 
Archiv f. Zellforschung. VII. 24 
