b e c r e a ted in th e sm a lle r a n d m o r e iso la t e d area o f w e s te r n A u s tr a ’ia. d iffe r en t from w h a t ea ste rn
A u s tr a lia p r e s en ts , s e em s a t fir st s ig h t fa v ou rab le to tb c id e a th a t th e s e arc d e r iv a tiv e g en e ra iinrl
sp e c ie s , fo rm ed d u r in g th e g ra d u a l m ig r a tio n o f c e r ta in o f th e O rd e rs and G en e r a o f th e c a s t toward s
th o w e s t. B u t o n th e o th e r h a n d , th is m a s s in g o f m o s t o f th e p e cu lia r fe a tu r e s o f th e A u str a lia n
F lo r a in th e w e s t , u um ix c d th e r e w ith P o ly n e s ia n , A n ta r c t ic , o r N ew Z ea la n d g en e r a , i s an a r g um en t
for r e g a rd in g w e ste rn A u s t r a lia a s t h e c en tr um o f A u s tr a lia n v e g e ta t io n , w h eu c c a m ig r a t io n proc eed ed
e a s tw a r d ; au d th e e a s te rn g en e r a an d sp e c ie s m u s t in su ch a ca se h e r eg a rd ed a s th e d e r iv a tiv e fo rm s.
H a d w e a n y id e a o f th e com p a ra tiv e g e o lo g ic a l a g e o t ea s te rn an d w e s te r n A u s tr a lia , th is in q u iry
m ig h t b e pro c e ed ed w ith a lit t l e fu r th e r ; th o u g h ev en th e n it w o u ld b e so o n b r o u g h t t o a s ta n d s
t ill, b y th e n e c e s s ity o t d e te rm in in g th e a n te c e d e n ts o f th e w h o le A u str a lia n F lo r a . T liis F lo ra ,
th o u g h m a n ife s tly m o r e a llie d t o th e In d ia n th a n to a n y o tlie r , differs from i t so o r g a n ic a lly , th a t
i t is im p o s s ib le to lo o k u p o n o n e a s d e r iv ed fr om th e o th e r , th o u g h b o th m a y h a v e h a d a com m o n
p a r en ta g e .
T h e lo c a l ch a ra c te r o t th e so u th -w e s te r n A u s tr a lia n id a n ts i s a n o th e r sin g u la r fea tu r e th a t m u s t
n o t h e o v e r lo o k ed in a n y in q u ir y a s t o th e r e la tiv e a g e s o f c o u n tr ie s an d th e ir v e g e ta tio n . S o
s in g u la r ly c ir cum sc r ib ed are i t s sp e c ie s in area, tb a t m a n y are fo u n d in o n e sp o t a lo n e , an d , o f
som e N a tu r a l O rd e rs, th e sp e c ie s o t Sw a n R iv e r differ v e r y m u c h fr om th o s e o f K in g G eo rg e ’s
S ou n d . I am q u ite a t a lo s s to o ffe r a n y p la u sib le rea so n fo r th is rap id su c e e s s io n o f fo rm s in area,
an d th e c o n tr a s t in th is r e sp e c t b e tw e e n th e so u th -w e s te r n a n d e a s te rn d is tr ic ts is a ll th e m o r e r e m
a rk a b le , b e ca u se th e la tt e r a lso , as com p a r ed w ith o th e r p a r ts o f th e w o rld , p r e s en ts a v e r y c o n s id
e rab le a ss em b la g e o f lo c a l sp e c ie s. B u t so i t is , th a t th e r e are far m o r e K in g G eo rg e ’s S o u n d
sp e c ie s a b s en t fr om tb e Sw a n R iv e r , th o u g h sep a ra ted b y o n ly 2 0 0 m ile s o f to le r a b ly le v e l la n d , th a n
th e r e are T a sm a n ia n p la n ts a b s en t fr om V ic to r ia , w b ic h ar e a s m a n y m ile s apart, an d sep a ra ted b y
a n o c e a n ic str a it. I t w o u ld in d e ed appear th a t th e m ix tu r e o f sev e ra l F lo r a s o f diffe r en t ch a ra cte r
in o n e ar ea ten d s t o k e ep d ow n th e t o t a l n um h e r o f sp e c ie s in th a t area, an d i f so , w e m a y c o n n e c t
th e r ic h n e s s in sp e c ie s o f th e w e ste rn A u str a lia n F lo r a w ith it s sin g u la r u n ifo rm ity o f charac ter ,
for i t is p u r e ly A u str a lia n , w ith o u t a dm ix tu r e o f a n y o th e r e lem e n t . A s th is e x c e s s iv e m u lt ip lic a t io n
m u s t , u n d e r th e th e o r y o f c r e a tio n b y v a r ia tio n , h a v e o c cu p ied a g r e a t le n g th o f tim e , i t s e em s
t o h e m o r e n a tu r a l to a ssum e , o n p u r e ly b o ta n ica l g r o u n d s, th a t th e w e s te r n A u s tr a lia n F lo r a is
t h e e a r lie s t, au d s e n t c o lo n is ts t o th e e a ste rn q u arte r , w h e r e th e y b e c am e m ix ed w ith In d ia n , P o ly n
e s ia n , e t c ., c o lo n is t s , th a n th a t th e w e ste rn F lo r a w a s peopiled b y o n e s e c t io n o n ly o f th e in h a b ita n ts
o f t lie e a s te rn qu arte r.
S o m u ch for th e b o ta n ic a l a sp e c t o f th e q u e stio n . T h e g e o lo g ic a l o n e s u g g e s ts a different
ex p la n a tio n . T h a t p a r t o f th e A u str a lia n c o n tin e n t w h ic h a lo n e is c lo th ed w ith an y con sid e rab le
am o u n t o f v e g e ta t io n , m a y h e lik e n e d to a h o r s c -sh o e o f m o r e or le s s e le v a ted la n d , w ith it s c o n v
e x ity t o th e n o r th , an d a v a s t en c lo s e d c e n tr a l dep r e ssed area, th a t o p en s to th e s e a o n th e so u th ,
an d ad v an c e s n o r th a lm o s t to . th e G u lf o f C arp en taria. A c c o r d in g to M r . J u k e s ’s c lev e r ‘ S k e tch
o f th e P h y s ic a l S tr u c tu r e o f A u s tr a lia ,’ th is c e n tr a l an d so u th e rn ar ea w a s r e c e n t ly an o c e a n ic h a y ,
a n d e x is t in g sp e c ie s o f M o llu s c a are fo u n d on i t s su r fac e for m a n y m ile s a lo n g th e c o a st, and in lan d
fr om it , in an a lm o s t u n c h a n g e d c o n d itio n .* T o th e e a s t o f th is dep r e ssed area, th e m o u n ta in s
are far lo f tie r and th e ro ck s o f a m u ch g r ea te r a g e th a n to th e w e s t o f i t ; an d w e r e th o q u e s tio n o f
th e a g e o f th e F lo r a s c om p r ised in th a t o f th e r o ck s th e y in h a b it, lit t le d o u b t w ou ld b e en tc r -
* Great beds of shells, with the colours retained, are found at Jurien Bay, at forty to eighty feet above the
sea-level. (Von Sommer, in Quart. Journ. Geol. Soc. v. p. 52.)
ta in ed t lia t th e w e ste rn o n e w as m o d e rn an d d e r iv a t iv e ; b u t in n o o th e r p a r t o f th e w o r ld are
r e c en tly -fo rm ed la n d s te n a n te d e x c lu s iv e ly b y en d em ic p la n ts , n o r d o th e y p r e sen t a s sem b la g e s o f
v e r y lo c a l s p e c ie s ; on th e con tr a r y , th e y arc in h a b ite d b y m a n y in d iv id u a ls o f a few sp e c ie s d e riv ed
from su r r o u n d in g co u n tr ie s, o f w h ich som e few are so a lte r ed a s to b e d is tin g u ish e d a s v a r ie tie s or ev en
s p e c ie s ; an d w e c a n n o t th e r e fo r e a c c ep t th e g e o lo g ic a l ev id en c e a s g o o d for e x p la in in g th e b o ta n ica l
p h en om en a .
T h e r e i s a n o th e r w a y o f v iew in g th e w h o le q u e stio n , b u t o n e so p u r e ly sp e cu la tiv e t lia t I lic s i-
ta te t o p u t i t forward. I t i s th a t th e a n te c ed en ts o f th e p e cu lia r A u s tr a lia n F lo r a m a y h a v e in h a b
ited an ar ea to th e we stw a rd o f th e p r e s e n t A u str a lia n c o n t in e n t, an d th a t th e cu r io u s a n a lo g ie s
w h ic h th e la t te r p r e s en ts w ith th e S o u th A fr ic a n F lo r a , a n d w h ich a r c so m u ch m o r e c o n sp icu ou s
in th e so u th -w e s t qu arte r, m a y b e c o n n e c ted w ith su ch a prior s ta t e o f th in g s .
5 7,
0?i th e F lo r a o f C o u n trie s ai'ou n d Spence7''s Gulf.
S o u th A u s tr a lia , w h ic h n ow ran k s as a d is tin c t c o lo n y , h a s b e en b u t im p e r fe c tly explored,
and is appai'e iitly v e r y po o r in sp e c ie s. S om e n o t ic e s o f it s b o ta n y w ill b e fo u n d in L in d le y ’s and
H o o k e r ’s A p p en d ic e s t o M it c h e ll’s J o u r n e y s ; in B r ow n ’s ‘ A p p e n d ix t o S tu r t ’s J o u r n e y ;’ in H o o k e r ’s
‘ K ew M is c e lla n y ,’ 1 8 5 3 , p. 1 0 5 ; an d , m o r e r e c e n t ly , in M u e lle r ’s R ep o r t o n th e p la n ts c o lle c t e d b y
Mr . D . H e r g o lt d u r in g B a b b a g e ’s e x p ed itio n . T h e y a ll sh ow th a t th e ch a ra c te r o f th e F lo ra is
in te rm ed ia te b e tw e en tb c so u th -e a s te r n , so u th -w e s te rn , a n d tr o p ic a l F lo r a s, th e e a s te rn b c iu g perhaps
th e d om in a n t, au d th e tr o p ic a l d u e to th e p ro x im ity o f th e c en tr a l de se r t.
A m o n g s t th e w e ste rn g en e r a au d sp e c ie s w h ich h e r e approach th e ir e a s te rn lim its arc Hih'iscus
h a k eoe fo lm s a n d m u ltifid u s , C ya n o th am n u s, S oU ya h e te ro p h y lla , C h e ira n th e ra , B o s s iæ a su lc a ta , T em -
p le to n ia r e tu sa , C lia n th u s D am p ie r i, N itr a i'ia B iila r d ie r i, A d e n a n th e r a te rm in a lis , P o d o th e c a , C y lin -
d ro so ru s f ia v e s c en s , L o g a n ia o 'a s s ifo lia , A n th o c e rc 'is a n isa n th a , C y c lo th e c a a u s tr a lic a , an d Codono-
ca rp u s a c a c iæ fo rm is ?
T h e tro p ica l e lem e n t i s d isp la y ed b y sp e c ie s o f C r o ta la r ia , P o ly c a r poe a , M o n en te le s, P lu ch e a ,
G lo sso g yn e , S a r c o s tem m a , T r ich o d e sm a , R o s te llu la r ia , an d S a n ta lum . M u e lle r fa r th e r a llu d e s to a
su c cu len t, lea fless E u p h o r b ia , p robably o f th e In d ia n o r S o u th A fr ic a n ty p e . T h e a b sen c e or ra r ity
o f P ro te a c eæ , Sopho7'eæ, M y r ta c eæ , D io sm eæ an d E p a c r id eæ , and p r ev a len c e o f Com p o sitæ , Ereiyio-
p h ila , Z y g o p h y lleæ an d S a lso leæ , are o th e r p roofs o f th e tr o p ic a l an d d e s e r t ch a ra c te r o f th e S o u th
A u s tr a lia n F lo r a .
F r om th e e x am in a tio n o f a c o n sid e ra b le c o lle c tio n o f S o u th A u str a lia n sp e c ie s m a d e b y M e ssr s.
W h ita k e r , D u t to n , I lille b r a n d t , e tc ., I am in c lin e d to su sp e c t tb a t it c o n ta in s so few pe cu lia r g en e ra ,
and so la r g e a n um b e r o f sp e c ie s w h ich arc c ith e r id e n tic a l w ith or s tr ic tly in te rm e d ia te in ch a ra cte r
b e tw e en e a s te rn and w e ste rn o n e s , or w h ich are so c lo s e ly a llied to c o n g en e r s o f o n e or th e oth e r ,
th a t th e y w ill fa v ou r th e id e a o f th e F lo r a b e in g to a ve ry g r e a t e x te n t d e riv a tiv e .