‘ Heterotypical Reduction ; in Somatic Cells . 779 
a more ‘ primitive ’ condition ; and suggest that the abnormal occurrence of 
heterotype reduction-figures may be regarded as a direct reaction to certain 
classes of stimuli. On the other hand, Laibach, in reviewing the position, 
strongly supports Strasburger in his view that such a reversion does not 
occur ; and in a recent paper on the action upon mitosis of certain toxic 
solutions, Stockberger disputes Nemec’s data, and attributes his results, as 
also those of some other authors, largely to the action of the distilled water 
used in the chloral hydrate solution. 
The question of the occurrence in somatic cells of heterotype reduction 
is one which bears upon problems of the widest interest. Among such may 
be mentioned those of heredity, of the nature of the processes occurring in 
hybrids, or, again, of those which obtain in pathological growths. The 
importance therefore attaching to it, together with the uncertainty in which 
it had been left, seemed to demand a re-examination of the phenomena 
concerned. The series of experiments here described were consequently 
undertaken in the hope of obtaining more definite data. 
Method. 
The plants used for experiment were cultivated at the Chelsea Physic- 
garden by Mr. Hales, to whom I am much indebted for a constant supply 
of suitable material. After some preliminary experiments with pea, bean, 
hyacinth, onion, and Galtonia , three plants were chosen for examination ; 
namely, Galtonia or Hyacinthus candicans , Vicia Faba , and Pisiim sativum . 
These were grown under the optimum conditions obtainable, either in damp 
sawdust or over water, according to the nature of the plant, and only healthy 
individuals were selected for experiment. All the experiments were 
carried out with as little as possible disturbance of the roots, and were 
checked by normal controls which were taken through precisely the same 
processes of washing, fixing, &c., as were used in the preparation of the 
experimental tissues. A further series of controls was obtained by fixing 
some roots direct from the sawdust or water in which they had been 
cultivated, without any preliminary washings or unnecessary manipulation. 
By these means it was possible to isolate the specific effects of the drug used 
in experiment, and to eliminate from consideration those effects resulting 
from the methods of preparation. The object of the investigation being 
to ascertain the nature of the heterotypical figures described by Nemec, 
it was decided to follow the method of poisoning adopted by the latter, 
modifying it in detail, in the event of a wider range of data proving neces¬ 
sary. Young plants of Galtonia ) bean, and pea were placed with their 
root-tips immersed up to 2-3 cm. in dilute solutions of chloral hydrate. 
The times of immersion were varied from hr., f hr., 1 hr., 1 \ hrs. to 2 hrs. ; 
and three different percentages of chloral hydrate were used, namely i-o%, 
0-75 %, and 0-5 %. Of these alternatives the most favourable for producing 
