BENTHAM ON THE SPECIES AND GENERA OF PLANTS. 141 



that it is known how singular are the anomalies which occasionally 

 break out in the flowers of some Orchidese, where hyhridity is quite out 

 of the question. The wild hybrids described in Dianthus, Galium, 

 Hieracium, and Stachys, appear to me to be exceedingly doubtful ; and 

 in the single alleged instance among Gramineae, that of the hybrid 

 between JEgilops and Triticum, one of the parents at least is in a culti- 

 vated state. We must also bear in mind the observation of C. F. 

 Gaertner, how numerous are the genera, where several nearly- allied 

 species grow together in the greatest abundance all over Europe, and 

 are never known to hybridise. Such are Ranunculus acris, repens, and 

 bulhosus ; Brassica Sinapistrum and nigrum ; Stellaria Holodea and 

 graminea ; Geranium inolle, pusillum, and rotundifolium ; Potentilla 

 argentea, verna, reptans, and anserina, &c, &c. 



Admitting, however, that in the extensive and diversified Flora of 

 Europe, wild hybrids have been observed in some twenty to twenty- 

 five genera, if we consider that the species in those genera which will 

 hybridise are but few ; that the individuals raised are always very few, 

 and often isolated ; that they are either not reproduced in a second 

 generation, or their offspring is a further approach to the parent species ; 

 and that even two individuals sprung directly from the same two 

 parent species generally differ quite as much from each other as from 

 one of their parents; we shall find it very difficult to believe in the 

 permanent establishment of wild hybrid intermediate races, distin- 

 guished by positive characters ; and we cannot but reprobate the modern 

 practice of introducing into Floras and systematic works so-called hybrid 

 species, races, or varieties, with a pretended diagnosis, which are, in 

 fact, nothing but descriptions of individuals. The reader is thus misled ; 

 for the chances are that the diagnosis will not apply to any fresh in- 

 dividual he may find of the same hybrid. A mere indication in the 

 Flora or other work, under each parent species, of the existence or 

 suspected existence of hybrids with such and such other species, is 

 always sufficient for all legitimate purposes. 



None of the above observations apply to artificial hybrids, the sub- 

 ject of so much careful experiment on the part of W. Herbert, C. F. 

 Gaertner, A. Braun, Naudin, and others, whose labours have done much 

 towards elucidating the physiology of hybrids in general. But the 

 plants thus experimented upon were placed in exceptional circumstances; 

 and the results obtained bear but indirectly on the evidences of wild 

 hybridity, or are often indeed calculated in some measure to mislead. 

 The fact that artificial impregnation between certain species can be 

 effected with great facility, is no proof that these species, or others allied 

 to them, are the more apt to produce hybrids in a wild state. It is well 

 known, for instance, how numerous are our garden hybrids in the 

 genus Erica. When I worked up that genus for the Prodromus, I 

 had before me wild specimens from various collectors of almost every 

 Cape species, and often in considerable numbers, including the original 

 specimens of Masson, Mven, and others, from whom were obtained the 

 majority of our garden forms ; I examined them all with great care, as 



