194 



Aspidium dilatatum, the young, Aspidium spinulosum, and a blighted 

 frond, Aspidium dumetorum ; hence I concluded that we had but one 

 species of this family in Britain : the only just conclusion would have 

 been that Smith described but one. Cystopteris fragilis is described 

 three times by the same author ; Athyrium Felix-femina twice ; 

 Polystichum aculeatum twice ; and so on. These facts, logically 

 viewed, in no degree militate against the existence of many cognate 

 British species. The only just inference to be drawn from such facts 

 must bear reference to the ability or inability of the author. It can- 

 not bear on the plants which he does or does not describe. Well had 

 it been for me had I then read some clearly expressed treatise on 

 logic, like the masterly productions since published by Duval-Jouve 



and Mill. I might, in that case, have escaped manifold errors. 



***** 



Even with those who seek the truth with singleness of purpose, 

 several barriers exist to the attainment of precise knowledge : one, and 

 a most formidable barrier it is, may be observed in the almost ine- 

 radicable propensity to regard differences resulting from age as 

 indicative of specific distinction. I never recollect meeting with a 

 botanist who would wish to seize on a young dicotyledon, and raise it 

 to specific honours : I never saw an entomologist treasuring a cater- 

 pillar or a chrysalis, as something totally distinct from the imago : 

 neither do we see the botanist contrasting the seedling sycamore with 

 the giant oak ; nor the entomologist comparing the caterpillar of a 

 moth with a perfect butterfly ; yet such feats are commonly performed 

 by the collector of ferns, and the common characteristics of baby- 

 hood are regarded as indicating nondescripts. This is no recent 

 foible ; our great Ray made a species out of the seedling or larva of 

 Oreopteris ; and Smith, who detected the error, still gives the seed- 

 ling as a variety, and, with ludicrous gravity, designates it as Oreop- 

 teris /3. Why do we not follow the example of the botanist who rears 

 his plants from seed ; or the entomologist, who raises his butterfly 

 from the egg ? I do not counsel a pteridologist to reject all informa- 

 tion to be derived from seedlings, but most strenuously do I recom- 

 mend him always to regard them as mere stepping-stones to 

 knowledge, and as incidents in the life of a species, whose history is 

 not to be written until it has attained maturity. 



But, although the seedling of a fern is unavailable for scientific 

 description, the young frond of the mature plant is an invaluable 

 auxiliary, a safe pilot, in our search for truth ; and I believe there is 

 not a botanist living, who, had he watched the fronds of mature roots 



