196 W. WALDEYER. 
med. Wissenschaft, 1885, 5th Jan., and ‘ Arch. Slaves de 
Biologie,’ t. iv, fasc. 2, p. 230); further, in similarly shaped 
cells in the marrow (Flemming, Werner, Lowit, Denys, 
Geelmuyden, Cornil, and J. Arnold, by the last of whom the 
list of authors, here quoted, is given. Without any doubt 
mitosis has been observed also in cells of lymphatic glands 
(Flemming, J. Arnold). Flemming (60), as was pointed out 
at the beginning of this section, is of opinion that the pheno- 
menon was observed in true lymphoid cells, whereas Baum- 
garten (16) believes that the mitosis was seen only in the 
fixed, so-called stroma-cells of the lymph-glands. 
J. Arnold, in his frequently quoted work (4), comes to the 
conclusion that the wandering cells, colourless blood-corpuscles, 
lymph-cells, and the corresponding form of cells in the marrow, 
the spleen, and the lymphatic glands, are able to multiply 
according to the type of mitosis, but that absolute proof of it 
has not been brought forward ; at any rate, it may be doubted 
whether these cells divide only mitotically. Herein he 
agrees with Liéwit. In such cells as connective-tissue cells, 
especially in the cells of new formations, and the so-called 
giant-cells of the marrow, all kinds of deviations from normal 
karyokinesis have been recorded. Thus, frequently tri- or 
multi-polar figures have been met with, e.g. in pathological — 
new formations by J. Arnold and Martin (182). Rabl (165) 
also describes such a figure in a hematoblast in the spleen of 
Proteus. Mayzel (184) traced the mitotic division of a 
connective-tissue cell of a living Axolotl into four pieces. 
Denys (53) figures multifold mitosis in giant-cells, and Cornil 
(49) in sarcoma and carcinoma. Similar tri-polar nuclear 
spindles have been observed in plants. Unequal daughter- 
stars are mentioned by Rabl. J. Arnold has seen forms very 
different from the normal in marrow and spleen. Arnold, on 
the ground of his discovery, would adduce a new arrangement 
of the forms of nuclear division, and would distinguish : 
1. Segmentation, with two subgroups, the direct and the 
indirect. 
2, Fragmentation, also direct and indirect. 
