| 
' 
f 
with special reference to the occurrence of Amitosis, etc. 377 
| remarks on the fact that these cells, though advanced in age, still 
retain their living, streaming protoplasm, and include chlorophyll 
and starch. 
Some very remarkable results bearing on the meaning of 
amitosis have been obtained in connexion with the study of 
mycorhiza. Werner* showed that in the case of certain cells 
of infected roots of Listera and Orchis there is a kind of fragmen- 
tation which is not a dying condition, but a special adaptation in 
-an actively working nucleus. Shibata} also, who studied the 
-mycorhizal tubercles of Podocarpus, demonstrated that in the 
infected cells, which are digesting the fungus, the nuclei divide 
repeatedly by amitosis. This is not a death phenomenon, but 
must be regarded as a rapid means of nuclear multiplication. 
After the digestion of the fungus is ended, normal karyokinetic 
figures can often be seen in the multinucleate tubercle cells, 
) showing that the nuclei, after repeated amitotic divisions, still 
retain the power of dividing by mitosis. I am not aware that 
these results of Shibata’s have actually received confirmation 
from more recent workers, but, if they are correct, they are of 
fundamental importance, since it 1s scarcely possible to reconcile 
them with the theory of the permanence of the chromosomes— 
a theory which already shows symptoms of crystallismg into a 
dogma. 
The amitosis in the cortex and stele of Stratiotes aloides, 
described in the present paper, seems to be unique among re- 
corded cases in respect of the immature condition of the tissues in 
which it has been observed. It lends support to the view that 
amitosis is by no means always a senile phenomenon—a view 
which has, in recent years, been upheld by certain zoological 
writers{. This opinion has hitherto received little acceptation 
on the botanical side, perhaps because the attention of cytologists 
has been, of late, so closely riveted upon karyokinesis and, more 
particularly, meiosis, that other phases in the life of the nucleus 
have suffered comparative neglect. 
* Magnus, W., ‘‘Studien an der endotrophen Mycorrhiza von Neottia Nidus 
avis L.” Jahrb. f. wiss. Bot., vol. xxxv. p. 205, 1900. 
+ Shibata, K., ‘‘Cytologische Studien tiber die endotrophen Mykorrhizen,” 
Jahrb. f. wiss. Bot., vol. xxxvit..p. 643, 1902. 
+ See for instance Child, C. M., ‘‘ Studies on the relation between Amitosis and 
Mitosis,” Biol. Bull., Woods Holl, Mass., vols. 12 and 13, 1906 and 1907; Glaser, 
O. C., “A statistical study of Mitosis and Amitosis in the Entoderm of Fasciolaria 
tulipa var. distans,” Biol. Bull., Woods Holl, Mass., vol. 14, p. 219, 1908; Walker, 
C. E., The Essentials of Cytology, London, 1907, p. 30; Foot, K. and Strobell, E. C., 
*‘Amitosis in the Ovary of Protenor belfragei and a Study of the Chromatin 
Nucleolus,” Archiv f. Zellforschuwng, Bd. vu. p. 190, 1912. 
