312 The Irish Naturalist.' December, 



Early in the present year, however, we both agreed that 

 these puzzling intermediates were deserving of further study. 

 We accordingly paid many visits in company to the Cliffs and 

 their neighbourhood, gathered a full series, in various stages 

 of growth, of the suspected hj^brid and of its probable parents, 

 carefully noted their range and habit in the field, and, finally, 

 compared, both in fresh and dried specimens, their minuter 

 distinctions in flower and seed. The result was to convince 

 us that the intermediates first noticed by one of us in 1901 

 were indeed the outcome of a natural crossing of Senecio 

 Cineraria DC. with 5. Jacobcea L- This conviction may be 

 said to be based on circumstantial rather than on direct evi- 

 dence, since the extreme practical difficulty in the way of 

 producing artificial hybrids in such a genus as Senecio forbade 

 any attempt to check our conclusion by the crucial experiment 

 of making hybrids similar to those we found readj'-made at 

 Dalke}'. 



The available evidence may be most conveniently considered 

 under two heads : — first, evidence derived from the observed 

 combination or fusion in the intermediates of various 

 characters of their assumed parents ; second, evidence derived 

 from the peculiar distribution of the intermediates in relation 

 to these parents. 



Taking these heads of evidence in order, it may be noted in 

 the first place that the intermediates through all their diversi- 

 ties (and they vary greatly in their degree of approach to 

 S' Jacobcea on the one hand, or to S. Cine^'aria on the other), 

 preserve certain obvious distinctive characters by which they 

 may be discriminated at a glance. The stems and leaves and 

 involucres are always less tomentose than in S. Ci7ierariay 

 and more so than in S. Jacobcea, while the inflorescence is 

 alwa^'S more leafy, and the leaves themselves more finely 

 divided than in the former species, though less so than in the 

 latter. The general tone of colour of the foliage, too, is suffi- 

 cient in itself to distinguish the three plants even at some 

 distance, S. Cineraria being white, S. Jacobcea fresh green, and 

 the intermediate grey, partl}^ by reason of the underlying 

 green showing through the thin layer of tomentum, partly 

 from the colour of the tomentum itself Eight visits were 



