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230 DE. M. T. MASTERS ON THE MORPHOLOGY, 



of hereditary endowment or of reversion to an ancestral state, 

 and, on the other, of the changes resulting in adaptation to vary- 

 ing circumstances ; and, lastly, we may be present as on-lookers, 

 and even as gardeners are sometimes privileged to be actual as- 

 sistants^ the birth and development of new species. Whether, 

 however, the phenomena witnessed in the so-called Betinosporas 

 are survivals and vestiges of a former condition, or whether they i 



are the results of attempts to conform to new conditions, which 

 will ultimately result in " new species," is a matter that cannot 

 be stated with any certainty. Those appearances in the adult 

 plant which reproduce the characteristics of the seedling may 

 be due to reversion, but others may be instances of progressive 

 adaptation. 



The Seedling Plant. 



The characteristics presented in the process of germination 

 and by the seedling plant during its growth do not differ mate- 

 rially from those of flowering plants generally. Nevertheless, 

 there is a good deal of variation in minor points in different 

 genera. Thus it is, in general, easy to distinguish a seedling 

 Abies from a seedling Picea, and both from a Pinus; hence 

 the desirability, for purposes of discrimination, of taking note 

 of the differences which the seedling plants present. 



The investigation of the characteristics of seedlings derives 

 further interest from the relation they bear to the supposed 

 ancestral condition of the plants, from their bearing on the 

 varying physiological requirements of the young plant, and on 

 their power of adaptation to particular external circumstances. 



It is, however, requisite to exercise much caution in these 

 matters, as it occasionally happens that in different species of the 

 same genus different modes of germination occur, as, for instance, 

 iu the genus Araucaria, where, in some species, the cotyledons 

 are hypogeal and with a fleshy tigellum, epigeal in others. The 

 lobing of the cotyledons in Pinus or the variable number of the 

 seed-leaves may be indications of varying degrees of energy of j 



growth, rather than of direct hereditary transmission. 











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Germination. — The germination of the seed presents no very 

 special features ; the husk of the seed splits into two pieces or 

 irregularly, the radicle protrudes, descends into the soil, while 

 the tigellum or caulicle lengthens often to a considerable extent, 

 bearing at its summit the cotyledons still enclosed within the 

 husk till at length, by the arching of the upper end of the 



