Preface. vii 



been so limited, as to apply merely to Victorian species, or had 

 repetitions in the dichotomy not been entirely avoided. Then, as 

 stated already, the difficulty presented itself, to maintain closely 

 and uninterruptedly a systematic arrangement expressive of 

 consecutive nearest affinities. Again, only such marks of separa- 

 tion could be seized on, as at a glance would be apparent even to- 

 the unarmed eyes, and as would not be liable to considerable 

 inconstancy ; thus then embryonic characteristics and any others, 

 either much concealed or very minute, however important they might 

 be, could not be drawn, unless exceptionally, into use for a work, 

 which was to serve expeditious field-engagements mainly. Where 

 in some few cases the author was compelled, to resort to the 

 description of minute organs for discrimination, simply no other 

 characteristics existed for separating the complex of some plants 

 from that of some others ; but even in the instance of seizing on 

 the only mark of distinction, by which the Salsolaceae and allied 

 orders can comprehensively be removed from some other ordinal 

 groups, the mere crushing of a seed will suffice for recognising 

 instantly, even without microscopic aid of any kind, the starchy 

 contents of the seeds and the remarkable form of its embryo. 

 With the same ease might almost the detail-floral structure of our 

 numerous Acacias be noted as demonstrating differences of 

 externally similar species; and on this particular subject infor- 

 mation for home-studies might be sought in the " Iconography of 

 Australian Acacias " recently issued. 



The number of the species, admitted into this work, had they 

 been treated in a less conservative sense, could have been largely 

 augmented; but when we see, to cite an example, how in perhaps 

 a thousand plants of Caladenia Patersoni, the most beautiful and 

 also the most widely distributed of our terrestrial orchids, hardly 

 two are quite alike as regards their flowers, while the majority of 

 the individual plants are so sportive, that the species became 

 described under several names by various writers, we should pause, 

 ere we attempt to circumscribe supposed specific forms, and leave 



