ABNORMAL FKUNS. 



There are })leiity of fjood-lookiug spores on Laxtira irmtita, yet they 

 ■will not germinate. ' For the last ten years several pans of spores from 

 this fern have heen sown yearly without a single plant having heen 

 raised. 



It has heen also a question with the author as to whether some of the 

 forms of species that only hear sterile fronds may not also be hybrid 

 species. All the varieties of the species will reproduce the abnormal 

 forms as prolilicly as the normal ones, whilst a so-called hybrid species 

 will not reproduce. 



There are not only abnonnal varieties of fenis, but the nonnal forms 

 of different k)calities differ so that when the common forms of cei-tain 

 localities are gathered together thgy display in a marked degree the 

 departure fi-onr one form. 



In nature the progress of change in form is veiy slow, although in 

 the forms of some plants a more rapid development in some localities 

 can be ol)served ; thus, nearly all the Harts tongue ferns at Westward 

 IIo ; on tlie Castle Kocks, Scarborough ; and at Dawlish, are once or 

 twice branched or crested. These changes, however, become much more 

 rai)id when imder the most favourable circumstances, such as obtaining 

 a pedigree and continuing it. 



With regard to the origin of species, it is leamt from the doctrine of 

 evolution, that all are the descendants of a compai-atively few originally 

 created simpler forms ; this doctrine teaches, (I now qimte Sir Joseph 

 Hooker's admiralde Botany) : — 1st. That the descendnnt of every plant 

 departs more or less in character from its parents. 2nd. That of these 

 vai-iatinns, some are better fitted than othei-s, and even sometimes than 

 their jutreut was. to survive in the area the plant inhabits. 3rd. That 

 the conditions of the area are, like the iiulividuals, variable. 4th. That 

 the number of deaths previous to maturity amongst the descendants is 

 enormously greater than that of survivors, and that these deaths are due 

 to the conditions of the area not having suited them. .5th. That the 

 doscondants best fitted to thrive under the coiiditions of the area will be 

 tlie survivoi-s. (>th. That these variations will hence ultimately, in 

 certain places, supplant the parent form ; and 7th. Tluit the difference 

 between a species and a variety being one of degree only, the variations 

 uccuniulated through successive generations will become speciHc, and these 

 again by a like process generic, and so on. 



No investigations demonstrate in a more striking manner the truth of 

 the Darwinian theory than such as this paper briefly illustrates. There 

 is undoubtedly a mathematical law in the changes of form, and this fact 

 provos t)»at Dr. Darwin's discoveries have vastly advanced our luiowledga 

 of the laws of nature. 



=;?p 



ON AN IMPROVED ANEROID BAROMETER. 



BY W. J. HAKUIbON, ESQ., F.G.S. 



An instninient which shall accurately indicate differences in level or 

 hciglit above the sea is mucli needed by practical nion of science. The 

 geologist requires it to ascertain the varying heights of his beds of rock, 

 the zoologist and the botanist to know the limits of the zones of animal 

 and vegetable life, and it is of not less service to the meteorologist, the 

 surveyor, the engineer, nnd tlie tiavoUer. 



