The Making of Species 
variety,” writes De Vries (p. 228), ‘‘ the flower is 
suppressed, and the loss is attended by a corres- 
ponding increase in the number of pairs of bracts. 
This malformation results in square spikes, or 
somewhat elongated heads, consisting only of the 
greenish bracts. As there are no flowers, the 
variety is quite sterile, and, as it is not regarded 
by horticulturists as an improvement on the 
ordinary bright carnations, it is seldom multiplied 
by layering. Notwithstanding this it appears 
from time to time, and has been seen in different 
countries and at different periods, and what is of 
great importance for us, in different strains of 
carnations. Though sterile, and obviously dying 
out as often as it springs into existence, it is 
nearly two centuries old. It was described in the 
beginning of the eighteenth century by Volckamer, 
and afterwards by Jaeger, De Candolle, Weber, 
Masters, Magnus, and many other botanists. I 
have had it twice at different times and from 
different growers.” Similarly, the long-headed 
green dahlia arose twice over some years ago in 
the nursery of Messrs Zocher & Co. 
Further, the peloric Toad-flax (Zzxarza vul- 
garis peloria) is, De Vries informs us, ‘‘ known to 
have originated from the ordinary type at 
different times and in different countries under 
more or less divergent conditions.” And, as this 
variety is wholly barren, it must in each instance 
have had an independent origin. Lastly, the 
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