ON THE EUROPEAN SPECIES OF FESTUCA. 303 



following, which is a free translation: — "If we look upon a species 

 as something created (Geschaffenes), as Jordan does, we must hold 

 as species all distinguishahle and recognisable forms ; if, on the 

 other hand, we have learnt to regard a species as something 

 developed (Gewordenes), if we believe that the numerous nearly 

 allied forms of a certain group are all of them descendants of a homo- 

 geneous parent form A, but were subject to very varied conditions ; 

 whilst another form B, synchronously with A, was subject to very 

 little or no variety of conditions, appearing now as a homogeneous 

 whole — we may express this state of things by saying that the 

 whole group of forms which proceeded from A is equivalent to the 

 single form B, and we may term each a species, viz., the whole 

 group represented by A, and the single form B." 



Prof. Hackel has paid much attention to the behaviour of the 

 various forms of Festuca under cultivation, raising them from seed 

 where possible, though he finds this less easily practicable than 

 might be expected, in consequence of the numerous cases in which 

 the fruit is not brought to perfection. He declares, however, that 

 little can be learnt from cultivating, for he finds all forms, even 

 subspecies and sub varieties, are reproduced with characters as 

 distinct as in the originals, and that even the weaker characters, 

 such as the absence of an awn in F. ovina var. capillata, ofi^er no 

 exception. 



Variations produced by situation (standorts-formen) are, how- 

 ever, not constant ; for instance, in damp shady places all the parts 

 become weak and bent, the leaves lengthen and become thinner, 

 the sclerenchyma becomes weaker, the colour of the green is deeper 

 or yellower, the folded leaf becomes open, the florets are more 

 delicate and loosely placed. In dry situations the parts become 

 more rigid, thicker, shorter, more closely placed together, the 

 colour glaucous. All these characters disappear in the first 

 generation if the conditions be changed. Again, in heavy soil the 

 runners are short ; in loose soil, long. It is easy to recognise the 

 peculiarities of character which are induced by situation ; but 

 we must not forget to distinguish permanent forms induced by 

 one and the same peculiarity of situation throughout an end- 

 less series of generations, such as F. ovina-alpina and F. {rubra) 

 sabidicola, Duf. 



Prof. Hackel devotes several pages to an explanation of his 

 opinions as regards the relative value (Dignitat) of the forms, and 

 of the method by which he arrives at the grouping into species, 

 subspecies, varieties, and subvarieties ; but unfortunately I find his 

 style and language so involved and wordy that it is difficult to give 

 a distinct and clear idea of his reasoning. At page 52 he says that, 

 for estimating the value of forms, the following may serve as prac- 

 tical criteria : — The number of distinctive characters, but especially 

 their relative absence or presence, in numerous examples, in a 

 weaker or more inconstant manner ; or their presence in com- 

 bination with those of another and distinct form. He then goes 

 on to explain that such mtermediate forms which obliterate 

 boundary lines become always more numerous as we adopt lower 



