Botany. — On Hypotriploid Dwarf-hyacinths derived from Triploid 
Dutch Varieties through Somatic Variation.” By W. E. pr 
Mor. (Communicated by Prof. J. C. Scnours). 
(Communicated at the meeting of December 23, 1921). 
I. Introduction. 
Among the varieties of Dutch hyacinths, which in my cytologie 
investigation I found to be heteroploid, there are a couple which 
produced a comparatively large number of budvariations: varying in 
form as well as in colour. They are the single triploid varieties 
Grand Maitre (colour: pure mauve), and King of the Blues (colour: 
+ like Prussian-blue). 
In my publication: “De Pewistence de variétés hétéroploides de 
Hyacinthus orientalis L. dans les cultures hollandaises” 1 made 
mention of a large, elongated form of Grand Maitre, termed by 
me Grand Maître giganteus whose morphological aspect of chromo- 
somes, so far as could be made out, is exactly the same as that of 
the parental variety. Furthermore, I pointed out that small bulbs 
also agreed in number, shape and size of the chromosomes, so that 
this growth-retardation had to be ascribed to external circumstances. 
As to the variety King of the Blues I reported only parenthe- 
tically, that morphological change was observed with a vegetative 
increase. In the autumn of 1920 and in 1921 1 was in a position 
to establish, without sacrificing all my anomalous plants, that what 
I had wrongly presumed regarding Grand Maitre, proved to be a 
fact, viz. that through vegetative increase dwarf-plants could arise 
independently of each other, characterised by a smaller number of 
chromosomes in the root-cells, which number was still the same 
after years of vegetative propagation. 
Many conjectures may be made as to the cause why it is just 
the Grand Maitre and the King of the Blues which are characterised 
by marked. budvariations: 1. that these varieties are heterozygous 
triploid; 2. that they are grown in large numbers; 3°. the mentioned 
facts combined. 
