ITI SUDDEN VARIATION 153 



year previously isolated in order to prevent hybridisa- 

 tion. 1 A year later, a similar fact was observed by 

 another horticulturist when all of a sudden a large 

 number of plants of Narcissus} which had met with 

 adverse circumstances and had required some quan- 

 tity of chemical manure, began to bear double 

 flowers. 



Among animals, sudden variation is not uncommon, 

 mainly through the disappearance of some external 

 characters. In Paraguay, during the last century 

 (1770), a bull was born without horns, although his 

 ancestry was well provided with these appendages, 

 and his progeny was also hornless although at first 

 he was mated with horned cows. If the horned and 

 the hornless forms were met in fossil state, we would 

 certainly wonder at not finding specimens provided 

 with semi-degenerated horns, and representing the 

 link between both, and if we were told that the horn- 

 less variety may have arisen suddenly we should not 

 believe it, and we should be wrong. In South America 

 also, between the sixteenth and eighteenth centuries, 

 the Niata 3 breed of oxen sprang into life, and this 



1 Cf. A. Carriere, Spontaneite simultanee. Rev. Horticole, 1882, 



P- 534- 



2 M. Poulin, Particular ites Vegetahs. Ibid. 1883, p. 342. 



3 Niatas are occasionally met with in Europe, and many are living at 

 present. They are descendants of common cattle and sheep, and no 

 particular reason for their peculiarity is offered. This sort of variation 

 thus seems to be common. 



