On the Question of the Occurrence of ‘ Heterotypical 
Reduction 5 in Somatic Cells. 
BY 
H. P. KEMP, 
Imperial College of Science , South Kensington. 
With Plates LXVI and LXVII. 
D URING the last few years an increasing interest has centred round the 
problems presented by the processes which underlie the structural 
changes of nuclear and cell division. In particular, attention has been 
directed to the occurrence in some plant and animal tissues of certain 
deviations from what are held to be the normal character and sequence 
of events. It has been shown by various observers that such abnormalities 
as imperfectly separated nuclei, multipolar spindles, and chromosomes of 
peculiar shape may be induced artificially, as by the application of certain 
drugs, by sudden changes of temperature, or by mechanical stimulation. 
Attempts have been made to bring these experimental phenomena into line 
with those which have been shown to occur in some morbid growths ; 
it is indeed evident that the possibility of so inducing structural modifica¬ 
tions, comparable to those occurring naturally in certain pathological 
conditions, is one of great interest, and presents valuable opportunities of 
experiment. 
From the numerous researches in this field have emerged two chief 
problems, which are at present giving rise to considerable controversy. 
These are : (i) the possible occurrence of a phase of amitosis in the cells of 
the higher plants and animals ; and (2) the possible existence in somatic 
cells of a capacity for heterotypical reduction of their chromosome number. 
The present paper deals chiefly with the second of these two problems. 
The question of amitosis was first brought forward in 1902, by 
Wasielewski, who stated that, under the influence of a dilute solution of 
chloral hydrate, a phase of amitotic division occurred in the root-cells of pea, 
bean, onion, &c., followed by a return of apparently normal mitosis. 
Wasielewski concluded, and in this conclusion he is supported by Nathan- 
sohn, that, contrary to the opinion then generally held, this must be regarded 
as evidence of the interchangeability of the two processes. In 1902-4, 
however, his work was repeated by Nemec, who disputed the above con- 
[ Annals of Botany, Vol. XXIV. No. XCVI. October, 1910.] 
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