Dec. 1, 1S6S.] 



HARDWICKE'S SCIENCE-GOSSIP. 



267 



Prior, " following Hudson, have shifted the hyphen 

 and chosen to understand the name as ' Eemale- 

 horse Tail,' or Marestail ! " The two names are, 

 therefore, now recognised as belonging to two 

 different plants. Why, then, is it that not only 

 do writers of no importance continually confuse the 

 two, but even Dr. Hooker, in his admirable address 

 lately delivered before the British Association at 

 Norwich, speaks of the Equisetacea as containing 

 but one recent genus, " that of the common Mares- 

 tails of our river-banks and woods." This is the 

 more misleading, as, although the Hippuris was 

 once called Horsetail, we have no grounds for 

 asserting that the Equiseta were ever known as 

 Marestail ; except to a lady whom I heard on one 

 occasion dilating upon the Wood Horsetail (E. syl- 

 vaticum), barren and fertile plants of which were 

 before her, who informed her companion that " this 

 (the barren spike) was the Horsetail, and that (the 

 fertile one) the marestail; this is the male, and 

 the other the female ! " 



Wliy are " splitters " and " lumpers " antago- 

 nistic ? Probably because the " splitters " accuse the 

 " lumpers " of a tendency to generalize, to ignore 

 slight differences, to accept things as they appear to 

 be, without clue investigation : because, too, a chief 

 among them, while uniting many plants generally 

 considered distinct, admits, as species, in the genus 

 to which he has paid particular attention, two forms 

 at least as nearly allied as many which he rejects. 

 On the other hand, the " lumpers " accuse the 

 " splitters " of raising slight and trivial differences, 

 such as those caused by soil, situation, or other 

 accidental circumstances, to too great importance ; 

 because, too, a chief among them, in his maturer 

 age, has seen the necessity of withdrawing more 

 than one " species," which, in his younger clays, he 

 laboured hard to establish. Both parties will 

 probably in time discover what Tennyson calls "the 

 falsehood of extremes," and acknowledge the truth 

 of the old maxim, "in medio semper tutissimus 

 ibis." 



My last query is one which brings me back to 

 Mobberley, for there it was forced upon me ; and I 

 hope some reader of Science-Gossip will be able to 

 answer it. Why is the Tormentil (Eotentilla tor- 

 mentilla) separated from the Creeping Cinquefoil 

 (P. reptaus) ? or, what are the specific differences 

 between the two ? To quote the words of the late 

 lamented Artemus Ward, when he astonished the 

 congregation by replying to the preacher's question, 

 " Why was man made to mourn ? "— " I give it up." 



B. 



Hawthorn Blossom in October.— During a 

 stroll between Finchley and Hornsey last week, I 

 observed a hawthorn covered with blossom, while, 

 mingled with its snowy burden, were the red haws 

 of the previous May.— E. West. 



VARIATION IN THE HAWTHORN. 



A MONG the many questions now violently 

 -*-*- agitating the scientific world, there is perhaps 

 none more widely discussed by the world at large, 

 and none upon which it is less capable of passing 

 judgment, than the " origin of species." The sub- 

 ject is one that requires not only an extensive 

 knowledge of natural history and geology, but also 

 a certain freedom from prejudice, a willingness to 

 abide by the evidence of facts, and a firm reliance 

 upon the results of just reasoning founded upon 

 such evidence, whatever, and how startling soever, 

 the conclusions arrived at may seem. Negative 

 evidence in this as in other subjects is untrust- 

 worthy and of little or no value. The opponents of 

 Darwin's theory frequently assert that by natural 

 selection and variation no single species of animal 

 or plant has ever been known to have been produced 

 in historical times. Admitting this assertion to be 

 correct, no inference of any value can be deduced 

 from it. Eor we would ask, are the descriptions of 

 organized nature so numerous and exact that we 

 know every plant and animal to be to-day in struc- 

 ture and appearance identical with what it was 2,000 

 or 3,000 years ago? Had the study of natural 

 history acquired such wonderful perfection at so re- 

 mote a period as to warrant this conclusion ? I 

 trow not. The assertion is puerile and ridiculous. 



There is, however, in almost every natural order of 

 plants some genera that certainly appear to speak in 

 favour of such a formation of species by variation. 

 How else are we to interpret the confusion among 

 botanists of eminence as to the extent of such 

 genera as the Rose, the Willow, the Bramble, the 

 Violet, the Ranunculus, and others ? In each of these 

 genera there are a number of forms, upon the value 

 of which the very best naturalists disagree ; some 

 ranking them as true species, and others as mere 

 varieties. The very fact, however, of their being 

 thus ranked by skilful botanists as species clearly 

 shows that they are at least more or less distinct and 

 persistent varieties. But varieties, once become 

 persistent, can only be regarded as species ; for 

 wherein do they differ? Certain great groups of 

 plants, including the above, are at present extremely 

 active in originating new varieties. We are strongly 

 impelled, when we review our existing plants, and 

 observe how intricate and close is their alliance, — 

 we are strongly impelled to regard these variable 

 plants of the present day as the common parents of 

 future genera and species. A more minute and 

 accurate study of supposed species, such as is at 

 present being carried on by M. Jordan at the head 

 of continental botanists, can scarcely fail to throw 

 much light upon the power of plants to vary, and 

 indirectly upon the " origin of species by variation 

 and natural selection." The formation of varieties, 

 then, though perhaps as yet proving nothing, points, 



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