All such biological factors require to be analysed before the status of any genus 

 can be regarded as satisfactorily assured. The general tendency of recent years has 

 been to lay extreme emphasis on the details of sexual processes and the gametophyte 

 generation ; partly from an exaggerated veneration for anything sexual, and partly 

 from the idea that the somatically deteriorated gametophyte, being the remains of an 

 aquatic phase of reproduction, must be consequently older or more ' conservative ' in 

 its details than the giant timber-tree with the up-grade organization of dominant 

 land-flora. Yet both generations must be equally of algal origin, and sexual processes 

 are probably significant only so far as they relate to the phenomena of meiosis 

 established in the sporophyte stage. Asexual reproduction is as archaic as sexual, 

 and the advancing specializations of the photosynthetically independent forest-tree in 

 its progression from a sea-weed are quite as likely to give a permanent racial record 

 as may the deteriorated heterotrophic prothallia. 



Also it may be noted that any race or genus may present independent progression 

 along any of these lines at any time. No race is now likely to be wholly primitive, 

 and all are survivors of a past age, specialized in some respect. Thus Ginkgo, 

 accepted in recent years as a unique ' Link with the Past ', on account of its retention 

 of Zoi'dogamic fertilization by motile antherozoids, has a shoot-system and timber 

 anatomy of high grade, a fruit-formation as advanced as that of the Taxoid, though 

 retaining a foliage-leaf evidently much older than the needle-form of the majority. 

 Araiicaria may be archaic in many respects, but there is nothing in the progression 

 of still older groups (Pteridophyta, Cycadales) to suggest that such features have any 

 claim to be regarded as primitive, as the multiple production of vegetative nuclei in 

 a coenocytic male prothallus, or the germination of pollen-grains at a distance from 

 the micropyle. 



XII. Monstrosities : Though the individual plant is to be regarded not only as 

 a living mechanism, growing under certain conditions of environment, but as the 

 modern expression of a racial organization continuing a mechanism of response to the 

 conditions of past ages, and thus now working by inherent rules (Heredity) established 

 by Natural Selection, it is always subject to a certain range of error, beyond mere 

 ' continuous variation ' as an oscillation about a mean. All morphological specialization 

 may be scheduled in definite sets of growth-factors, including factors of form and 

 time-factors or rates of growth, and these must have some material counterpart 

 somewhere in the organism. It is generally supposed that the chromosomes of the 

 nuclei are the seat of such determinants ; and in the production of any special growth 

 the nuclei of the apical meristems, which remain permanently ' embryonic ' and 

 presumably contain all or a majority of such factors, segregate certain sets for this 

 purpose ; others not wanted are ' suppressed ' or become ' dormant ' in the so-called 

 ' adult ' phase. 



In any such segregation of a set of factors required to work out a special morpho- 

 logical unit (a flower, leaf, special bud-construction, or any smallest detail), heredity is 

 never absolute, and any mechanism may go wrong at any time, and in any manner : 

 e.g. a factor may be lost or misplaced, or an entirely wrong set may be isolated. 

 Such mistakes without rule constitute ' sports ' or discontinuous variations ; and where 

 the error, to our senses, is hopeless and useless it commonly passes as a ' monstrosity ' 

 or ' freak ' (Teratology). If slight and non-injurious it may be termed a ' sport ' ; such 

 errors being commonly corrected in the same or another generation. If non-reversible 

 ('mutation') the new idea is subject to natural selection, and, if a success, may conceivably 

 initiate a new departure as a new ' species '. If a failure it only hastens the elimination 

 of the race. 



The term ' monstrosity ' is thus generally applied to some phenomenon at once 

 recognizable as anomalous ; i. e. breaking the rules of observed heredity ; and though 

 often throwing a suggestive light on the grouping of factors in linked sets, such 

 mistakes do not necessarily indicate any phyletic ' reversion ' to a more primitive form 

 (except by loss of a factor which may have been secondarily attained). Every such 

 monstrosity requires to be studied separately for what it may be worth, knowing that 

 from the errors of the mechanism one may possibly learn something of the causal 

 action. The possibility of such monstrous formations or freaks becomes the greater 

 as the mechanism (especially that of reproductive processes) grows the more complex ; 



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