1 iS(> ARBORETUM AND FRUTICETUM. PART III. 



dom happens before the banning of summer. On the other hand, very many 

 sorts, in intermediate localities, are intermediate also in their time of flowering. 

 Hence, the same kind, when it inhabits three different regions, cannot be 

 compared together in the same stage of growth in a living state; and, conse- 

 quently, three species may, in this way, be made out of one. Dr. Host farther 

 observes that a great impediment to the determining of what are really species, 

 arises from the sexes or a species often inhabiting localities very distant from 

 each other, and sometimes even different regions; and the beautiful figures 

 which illustrate this author's work, on the supposition that they are faithful 

 portraits, clearly show that the male and female differ very considerably in 

 their foliage and wood, independently altogether of their catkins. 



The great master in the genus Salix may be considered Professor Koch, 

 who has done more to advance a knowledge of this genus in his 12mo pam- 

 phlet of' (U) pages, l)c Saiicibus European Commcnfafio, published in 1828, than 

 the most voluminous of ancient or modern authors. The preface to this 

 pamphlet is so full of instruction as to the mode of studying this family of 

 plants, that we are confident that our readers will feel obliged to us for pre- 

 senting to them the following 



ract of Koch's Preface to his Commentary on the Genus Saliv. The author 

 after noticing the difficulties to be encountered in this genus, and referring to 

 what has been done by Linnaeus, Wahlenberg, Willdenow, Smith, and others, 

 notices the 1 19 species which had been sent to him by Schleicher, as found by 

 that botanist in Switzerland, and thus, as we have before observed (p. 145f>.), 

 making the total number of species of Salix 254. Of Schleicher's species, he 

 says that he could not find one that truly deserved the name. They are, he 

 a Ids, mere variations of species long since known ; and, for the most part, 

 different forms of one changeable species, viz., his own S. johylicifdlia. All 

 Schleicher's kinds are enumerated as species in Steudei's Nomenclator ; but 

 Koch treats them as spurious, he recognising not more than 50 truly distinct 

 European species. 



The manner in which Koch obtained his knowledge of the genus £alix is 

 thus given : — " For a number of years, I observed the willows growing wild 

 in the Palatinate ; also those I met with during my travels; and those which I 

 have found, during the space of four years, in the neighbourhood of Erlangen. 

 All the species, or singular forms, which I found growing wild were trans- 

 ferred to the garden ; and to these were added kinds sent by my friends 

 Mertens and Zeiher, an addition of no small importance. From the former I 

 rereived genuine English willows in a living state. The whole collection was 

 afterwards transferred to the Botanic Garden at Erlangen, where, neither care 

 nor expense being spared, it has since been much increased. From M. Otto, 

 director of the Botanic Garden at Berlin, 1 also received a number of kinds. 

 Of dried specimens I have received the whole collection of M. Seringe, from 

 that author himself; and the greater number of the Swedish, French, and 

 English willows, gathered in their native habitats, from Mertens; forming in 

 the whole a greater number of species of this genus than was ever before 

 available by one individual. 



'• Everj genus of plants has certain peculiar features, with which constant 



r?ation and repeated examination alone can familiarise us; but there is 



i, us in which it is so necessary as in that of »Salix, to investigate, not only 



culiar characters, but also the growth of the plants, both in a wild and a 



cultivated state, lie who endeavours to characterise a species, either from a 



dried specimen or from a cultivated plant, is always liable to be deceived in 



it-, characters Hence, amongst all the writers on willows from the time of 



Linnaeus, Vv'shlenbers alone has clearly described them. He travelled through 



Lapland, Switzerland, the Carpathian Mountains, and Sweden; examining 



t he kinds of this genua in their native places of growth ; and, following in his 



ps, came Beringe, also a most, diligent investigator. Taking these 



BUthoTS for my guide, although, in some instances, I have been compelled to 



differ from them, I here offer a synopsis of tin; European species of willow. 



" In arranging thii genus, and distributing its species, if we put near together 



