VOL. xvin. (3) NOTES ON HELOSCIADIUM 241 



1. " Great range of variation in habit and facies. This is 

 remarkably impressed on the mind if a line is taken from the 

 ordinary luxuriant Irish forms . . . through those from 

 Derrymore, Castleconnel, and Renishaw, to the curious little 

 form . . . from Portumna and Woodford " 



2. Great variability in foliage. 



3. Sterihty, which apparently (fide Gliick) persists even 

 in cultivation. 



4. Considerable vegetative development, at the expense 

 of the floral development ; this is in strong contrast to the 

 two " parent " species. 



5. Intermediate position between the " parents." This 

 does not hold true of all characters, of course. 



6. Neighbourhood of the " parents." 



The case for hybridity is not thus proved beyond cavil, 

 but it is strongly founded, and, I think, is strengthened by 

 one most interesting feature, and deductions from it, with 

 which this paper shall conclude. 



The plant is sterile, and yet it is very abundant where it 

 occurs. This is due to the fact, proved in my garden, where 

 it grows in pots kept in a tub of water, that it propagates 

 itself vegetatively. Broken off pieces of leaf take root and 

 form separate plants, as occurs e.g. with Cardamine pratensis, 

 etc. 



Now, if it reproduced itself by seed, the off-spring from the 

 seed would, according to Mendel's principle, vary much in 

 character, and always in certain well-defined directions and 

 proportions. But as it is reproduced vegetatively, it is in 

 any one locality singularly homogeneous. The conclusion is 

 that the whole of a local stock generally springs from one 

 original hybrid plant, whose characters are thus reproduced 

 faithfully in all its " vegetative " off-spring. But there are 

 one or two exceptions to this rule : one of them is found at 

 Haxey, N. Lincoln, where the species was gathered by G. 

 Webster in 1881 and 1884. Here it is very variable, both in 

 cut of leaves, and in length of style, though the specimens are 

 all on the small side. Some are very near inundatum ; but 

 capillary segments of the lower leaves are not to be found ; 

 and they are all Moorei. This variability at Haxey " means 



2 

 K 



