142 THE XUT CULTURIST. 



obscure and scarcely explainable ; as, for instance, its 

 virulence among some species and varieties, and almost 

 if not total absence among others. So far as my obser- 

 vation extends, I have never found it attacking the na- 

 tive beaked hazel (Corylus rostrata), and my correspond- 

 ents in the Northwest and in the Pacific States assure 

 me that no blight on the hazel has, as yet, been found 

 there, and its absence is probably due to the fact that 

 the common hazel (C. Americana] is not an inhabitant 

 of these regions. 



In a neighbor's garden just across the highway from 

 my own, there are, at this time, four old European 

 hazelnut trees, fully twenty feet high and as many years 

 old. They are of two varieties : one a small round nut, 

 the other a long, slender nut, but neither of much value, 

 because of their small size. The trees, however, are 

 perfectly healthy, never having suffered from the blight, 

 although these four are all that remain of a long row 

 of choice European varieties all planted at the same 

 time. Blight destroyed the better varieties, while these 

 inferior ones continue to thrive and are exceedingly 

 productive. 



This native fungus that causes blight in the hazels 

 is but one of a large number of similar maladies which 

 have appeared and often worsted the horticulturist, in 

 his endeavor to introduce and cultivate foreign species 

 and varieties of plants, and like the tropical fevers, they 

 may pass unnoticed among the natives, but are terribly 

 fatal to immigrants from cooler climates. The disease ' 

 so well known as the black knot (Ottilia morbosa, Schu.), 

 and widely destructive to the European varieties of the 

 plum, and Morello cherries, has existed for ages among 

 our native plums and black cherries, doing compara- 

 tively little harm ; but it seems to protest, by its viru- 

 lence, against the introduction of some foreign species. 

 The same is true with various blights and rusts which 



