DtTBLIN NATX7EAL HISTORY 80CIETT. 189 



dicate a plant of moist and sheltered places, while the rigid, contracted 

 foliage, the compact involucres, and stunted growth oiH. Wihoni indi- 

 cate a plant of exposed and dry rocks. Specimens, intermediate in 

 luxuriance, according to exposure, are, no doubt, common, the Tuu- 

 bridgense becoming stunted, and the Wilsoni luxuriant, without a cor- 

 respondent change in the character of involucre, which is regarded as 

 the " specific" character. Hence the advocates of species maintain that 

 j iixtaposition, under the same climatal conditions, without conformity, 

 is proof of specific distinctness. I cannot see how this can be main- 

 tained. If it were so, it might be argued that cauliflowers and cabbages 

 are distinct species because they may be grown side by side, and are 

 reproducible by seed from one generation to another ; and so, of fifty 

 other garden races which are to a great degree permanent, but which 

 are well known to have had a common origin. They all grow side by 

 side, unaffected by climate. ^ So also the cowslip and primrose, two 

 forms of Primula which differ from each other by far more obvious dis- 

 tinctions than the two Hymenophyllums, and which are equally con- 

 stant to their particular characteristics and habitats. The primrose 

 loves the shady or sheltered hedgebank or wood-side ; the cowslip delights 

 in open sunny meadows. They are found growing near each other, but 

 seldom intermixed, and the characters which separate them are floral 

 characters, and, therefore, technically of more importance than variation 

 in foliage would be considered ; and any botanist might appeal to his 

 experience of their unchangeable characters, and produce a case of pro- 

 babilities fully as strong as that adduced for the Hymenophyllums. 

 And yet, after having travelled with a triumphant case from Fair Head 

 to Cape Clear, we may find in the very last field at the point of Cape 

 Clear a primrose passing into a polyanthus. This would materially 

 shake his faith in one of his distinctive marks — the inflorescence ; and 

 if he also picked up an oxlip,he would find that the corolla was equally 

 variable. Hence he may be led to suspect that the primrose, oxlip, and 

 cowslip maybe only permanent races, not species; and the fact of their 

 occupying ftie same geographical area would not weaken his suspicions, 

 but, as I still venture to think, would materially strengthen them. And 

 we know that the progeny of both cowslips and primroses in cultivation 

 become polyanthuses ; and there is high authority for the further state- 

 ment that primrose, oxlip, and cowslip, have all been gro-vvn from the 

 seed of a single plant. Therefore, whether in our books we hold them 

 for species or not, in our inward convictions we regard them as perma- 

 nent races only, growing true to the sub-type in ninety-nine cases out 

 of a hundred, but sometimes breaking irregiilarly. Now, I would treat 

 the Hymenophyllums similarly ; as book species they are sufficiently 

 constant in their characters to have the honour of trivial names ; but, 

 viewed philosophically, the probabilities are in favour of their being, 

 like the primrose and cowslip, permanent varieties, rather than aborigi- 

 nal species. 



I am well aware that, were all plants thus treated, the number of 

 book species would be enormously reduced. But, notwithstanding, I am 



