o f t lie G en e r a and O rd e r s m o s t d e S d e n t in th e s e r e sp e c ts a r e so m a n ife s tly r ed u c ed m em b e r s o f
o th e r s , w h ic h a r e in d isp u ta b ly th e m o s t c om p le x in o r g a n iz a tio n in th e w h o le V e g e ta b le K in g d om ,
th a t n o g o o d c la s sific a tio n e v en b a s b e en fo u n d ed o n th e s e c o n sid e r a tio n s a lo n e .*
3 7 . A g a in , i t is a rg u ed b y b o th M r . D a rw in an d M r . W a lla c e th a t th e g en e r a l e ffe c ts o f v a r ia tion
b y s e le c tio n m u s t b e t o e s ta b lish a g en e r a l p r o g r e ssiv e d e v e lo pm en t o f th e w h o le a n im a l k in g d om .
E n t h e r e a g a in in b o ta n y wo a r e ch e ek ed b y th e q u e s tio n . W h a t is th e stan d a rd o f p r o g r e ssio n ?
I s i t p h y s io lo g ic a l o r m o rp h o lo g ic a l 1 I s i t e v id en c ed b y th e p ow e r o f o v e r c om in g p h y sic a l ob sta c le s
to d isp e r sio n or p ro p a g a tio n , or b y a n ic e ad a p ta tio n o f s tru c tu r e or c o n s t itu tio n t o v e ry r e str ic ted or
com p le x c o n d itio n s ? A r e c o sm o p o lite s t o b e r eg a rd ed a s su p e r io r t o p la n ts o f r e str ic ted r a n g e , h e r m
ap h r o d ite p la n ts to u n is e x u a l, p a r a site s to se lf-su s ta in e r s , a lb um in o u s-se ed ed to c x a lb um in o u s, g ym -
n o sp e rm s t o a n g io sp e rm s, w a te r p la n ts t o la n d , t r e e s to h e rb s, p e r en n ia ls t o a n n u a ls , in su la r p la n ts
t o c o n tin e n ta l ? an d , in fin e, w h a t is th e sig n ific a n c e o f th e m u lt itn d in o u s d iffe ren ce s in p o in t o f
stru c tu r e au d c om p le x ity , an d p ow e r s o f en d u ra n c e , p r e sen ted h y th e m em b e r s o f th e V e g e ta b le
K in g d om , an d w h ich h a v e n o r e c o g n iz ed p h y s io lo g ic a l en d a n d in te rp r e ta tio n , n o r im p o r ta n c e in a
c la ssific a to r y p o in t o f v iew ? I t i s e x tr em e ly e a sy t o an sw e r a n y o f th e s e q u e stio n s, an d to su p p o r t
th e o p in io n b y a h o s t o f a r g um en ts , m o rp h o lo g ic a l, p liy s io lo g ic a l, an d t c le o lo g ie a l; b u t a n y o n e g ifted
w ith a q u ick p e r c ep tio n o f r e la tio n s , an d w h o se m in d i s sto r ed w ith a su ffic ien c y o f fa c ts , w ill tu rn
ev e r y a r g um en t to eq u a l a d v a n ta g e for b o th s id e s o f th e q u e stio n .
T o m y m m d , liow ev e r , th e d o c tr in e o f p r o g r e ssio n , i f c o n sid e r ed in c o n n e c tio n w ith th e h y p o th e s is
o f t h e o r ig in o f s p e c ie s b e in g b y v a r ia tio n , is b y far th e m o s t p ro fou n d o f a ll th a t h a v e e v e r a g ita ted
th e s c h o o ls o f N a tu r a l H is to r y , an d I d o n o t th in k th a t i t h a s y e t b e e n tr e a ted in th e u n p r e ju d ic ed
sp ir it i t d em an d s. T h e e lem e n t s fo r i t s s tu d y a r e th e v a s t e s t an d m o s t com p lic a ted w liich th e
n a tu r a lis t c a n c o n tem p la te , a n d r e sid e in th e c om p r eh en s io n o f th e r e c ip r o c a l a c tio n o f th e so -c a lled
in o r g a n ic o n th e o r g a n ic w o r ld . G r a n tin g th a t m u ltip lic a tio n a u d sp e c ia liz a tio n o f o rg an s i s th e
e v id en c e an d m e a su r e o £ p r o g r e ssio n , th a t v a r ia tion e x p la in s th e ra tio n a le o f th e op e ra tion w h ich
r e su lt s in th is p ro g r e ssion , th e q u e stio n a r ise s. W h a t are th e lim it s to th e c om b in a tio n s o f p h y s ic a l
c a u s e s w h icb d e te rm in e th is p r o g r e ssio n , an d h ow ca n th e sp e c ia liz in g p ow e r o f N a tu r e sto p sh o r t o f
c a u s in g ev e r y ra c e o r fam ily u lt im a t e ly to r ep r e sen t a sp e c ie s ? W h ile th e p sy ch o lo g ic a l p h ilo sop h e r s
p e r su ad e u s th a t w e s e e th e t e n d e n c y t o sp e c ia liz e p e rv ad in g e v e ry a ttr ib u te o f o r g a n ic life , m en ta l
an d p h y s ic a l; an d tb e p h y s ic is ts te a ch th a t th e r e are lim it s t o th e am o u n t an d d u r a tio n o f h e a t,
lig h t , a n d e v e ry o th e r m a n ife s ta tio n o f p h y s ic a l fo r c e w h ich o u r s e n s e s p r e sen t o r ou r in t e lle c t s p e r c
e iv e , an d w h ich a r e a ll in pro c e ss o f c o n s um p t io n ; th e r e fle c tin g b o ta n ist, k n ow in g th a t h is u ltim a te
r e su lt s m u s t a ccord w ith th e s e fa c ts , is p e rp lex ed a t f e e lin g th a t h e h a s fa iled to e sta b lish o n in d e -
p e n d e n t e v id en c e th e d o c tr in e s o f v a r ia tio n an d p ro g r e ssiv e sp e c ia liz a tio n , or t o c o -o rd in a te hia
a t tem p ts to d o so w ith th e su c c e ssiv e d is c o v e r ie s in p h y s ic a l sc ien c e .
* The subject o f the retrogression o f types lias never yet been investigated in botany, nor its importance estimated
in inquuies of this nature. To whatever Order we may grant the dignity o f gi-eat superiority or complexity,
we find that Order containing groups of species of very simple organization; these are moreover often o f great size
and importance, and o f wide geogi-aphical distribution. Such groups, if regarded p e r se, appear to be far lower in
organization than other groups which are many degrees below them in the classified series; and our only clue to
their real position is their evident affinity with their complex c o -o r d in a te sd e s t r o y the latter by a geological or
other event, and all clue to the real position o f the former may be lost, Are such groups o f simply-coiistmcted
species ci-eated b y retrogressive variation of the higher, or did tlie higher proceed from them by progressive variation ?
If the latter, did the simpler forms precede in origin the highest forms o f all other gi-oups which rank below them
in the classified series ?
3 8 . B e fo r e d ism is s in g th is su b je c t, I m a y r ev e r t o n c e m o r e to th e op p o site d o c tr in e , w h ich
r eg a rd s sp e c ie s a s im m u ta b le c r ea tio n s, a n d th is p r in c ip a lly to ob se rv e th a t th e a r g um en ts in its
fa v ou r h a v e n e ith e r g a in ed n o r lo s t b y in c r e a sed fa c ilit ie s for in v e s t ig a tio n , or b y a d d itio n a l m e a n s
for o b se rv a tion . T h e fa c ts are u n a ssa ila b le th a t w e h a v e n o d ir e c t k n ow led g e o f th e o r ig in o f an y
w ild sp e c ie s ; th a t m a n y are sep a ra ted b y n um e r o u s s tru c tu ra l p e c u lia r it ie s fr om a ll o th e r p la n t s ;
th a t s om e o f th em in v a r ia b ly p ro p a g a te tb e ir lik e ; an d th a t a few h a v e r e ta in ed th e ir c lia ra c tcr s
u n ch a n g ed u n d e r v e ry d ilfe r en t c o n d itio n s a n d th r o u g h g e o lo g ic a l ep o ch s. R e c e n t d isc o v e r ie s lia v c
n o t w e a k en ed th e fo r c e o f th e s e fa c ts, n o r h a v e su c c e s s iv e th in k e r s d e riv ed n ew a r g um en ts from
t h em ; an d i f we h e n c e c o n c lu d e from th em th a t sp e c ie s are r e a lly in d ep en d en t c r e a tio n s and im m u ta
b le , th o u g h so o ften illim ita b le , th e n is a ll fu r th e r in q u ir y a w a ste o f tim e , an d th e q u e s tio n o f
th e ir o r ig in , an d th a t o f th e ir c la ssific a tio n in G en e ra an d Orde rs, can , in th e p r e s en t s ta te o f s c ien
c e , n e v e r b e an sw e r ed , an d th e o n ly k n ow n a v en u e s to a ll m e a n s o f in v e s tig a t io n m u s t b e c o n sid
e r ed a s c lo sed t i l l th e o r ig in o f lif e i t s e lf is b r o u g h t to lig h t.
3 9 . O f th e s e fa c ts th e m o st im p o r ta n t, an d in d e e d th e o n ly o n e th a t affords a ta n g ib le a r g um en t,
is th a t o f g e n e t ic r e sem b la n c e . T o th e ty r o in N a tu r a l H is to r y all sim ila r p la n ts m a y h a v e h ad o n e
p a r en t, b u t a ll d issim ila r p la n ts m u s t h a v e h a d d issim ila r p a r en ts. D a ily e x p e r ien c e d em o n stra te s
th e fir st p o s itio n , b u t i t ta k e s y e a r s o f ob se r v a tio n t o pro v e th a t th e se c o n d is n o t a lw a y s tru e .
T h e r e are, fu r th e r , c e r ta in c ir cum s ta n c e s c o n n e c te d w ith th e p u r su it o f th e s c ien c e s o f o b se r v a tio n
w h ich t e n d to na r row th e o b se rv er ’s v iew s o f th e a ttr ib u te s o f sp e c ie s ; h e b e g in s b y e x am in in g a
few in d iv id u a ls o f m a n y e x tr em e ly diffe r en t k in d s o r sp e c ie s, w h icb ar e t o h im fix ed id e a s, an d th e
r e la tio n sh ip s o f w h ic h h e o n ly d iscovei-s h y p a tie n t in v e s t ig a tio n ; h e th e n d is tr ib u te s th em in to
Gen e ra , Orde r s, an d C la sse s, th e pro c e ss u su a lly b e in g th a t o f r ed u c in g a g r e a t n um b e r o f d issim ila r
id ea s u n d e r a few su c c e s s iv e ly h ig h e r g en e r a l c o n c e p t io n s ; w h ils t w ith th e h isto r y o f t h e id e a s th em se
lv e s, th a t is , o f sp e c ie s, h e se ld om c o n c e rn s h im s e lf. Tu a s tu d y so v a st as b o ta n y , it ta k e s a lo n g
t im e for a n a tu r a lis t to arrive a t an a c cu ra te k n ow led g e o f th e r e la tio n s o f G en e r a an d Order s i f b e
aim a t b e in g a g o o d sy s t em a t is t , or to a cq u ire an in t im a te k n ow led g e o f sp e c ie s i f h e a im a t a
pro fic ien cy iu lo c a l F lo r a s, and in b o th th e s e p u r su its t lie a b stra c t co n s id e r a tio n o f th e sp e c ie s i t s e l f
is g en e r a lly lo s t s ig h t o f ; th e s y s tem a t is t se ld om r e tu rn s t o it , a n d th e lo c a l b o ta n is t, w h o fin d s th e
m in u te s t d iffe r en c e s to b e h e r ed ita r y in a lim ited area, ap p lie s th e a rg um en t de rived from g e n e t ic
r e sem b la n c e to ev ery h e r ed ita r ily d is tin c t form.
4 0 . I t h a s been u rg ed a g a in s t th e th e o r y th a t e x is tin g sp e c ie s h a v e ar isen th r o u g h th e v a r ia tion
o f p r e - e x is tin g o n e s aud t lie d e s tru c tio n o f in te rm ed ia te v a r ie tie s, th a t i t is a h a s ty in fe r en c e from a
few fa c ts in th e life o f a few var iab le p la u ts , and is th e r e fo r e u nw o r th y o f con fid en c e , i f n o t o f c o n s id
e ra tion ; b u t i t appears to m e th a t th e op p o site th e o r y , w h ich d em a n d s an in d e p e n d e n t c r e a tiv e a c t
for ea ch sp e c ie s, is a n eq u a lly h a s ty in fe r en c e from a few n e g a t iv e fa c ts in th e lif e o f c e r ta in sp e c ie s ,*
o f w h ic li som e g e n e r a tio n s h a v e proved in i'ariab le w ith in o u r e x tr em e ly lim it e d exp e r ien c e . T h e se
th e o r ie s m u s t n o t, liow ev c r , b e ju d g e d o f s o le ly b y th e for ce o f th e v e ry few ab so lu te fa c ts o n w h ich
th e y are b a s e d ; th e r e arc o th e r c o n s id e r a tio n s to b e ta k e n in to a c c o u n t, and e sp e c ia lly th e co n c lu s io n s
to W'liich th e y lea d , and th e ir b ea r in g up on c o lla te r a l b io lo g ic a l p h en om en a , u n d e r w h ich p o in ts o f
v iew th e th e o r y o f in d ep en d en t c r e a tio n s appears to m e to b e g r e a tly a t a d isa d v a n ta g e ; for a c co rd in g
to i t ev e ry fa c t an d ev e ry p h en om en o n r e g a rd in g th e o r ig in and co n tin u a n c e o f sp e c ie s, b u t th a t o f
th e ir o c c a sio n a l v a r ia tion , an d tb e ir e x tin c t io n b y n a tu ra l cau se s, an d r e g a rd in g tb e r a tio n a le o f c la s s i-
* See paragrapli 4 , wliere I have stated that the grand total of unstable species probably exceeds that o f the