DR. HOOKER ON THE BALANOPHOREJE. 97 



as those may be termed which are founded on the imperfec- 

 tions of organs ; " and he takes the most perfectly developed 

 species as the best exponents of the typical structure of any 

 group, — a principle laid down, we believe, by Mr. Brown. 

 This gives a substantial scientific basis for the estimation of 

 affinity. Agreement in plan of structure is just what consti- 

 tutes affinity ; agreement in grade of evolution may indicate 

 only distant analogy, can indicate only collateral relationship, 

 — not to be neglected, indeed, but in itself of no account 

 in assigning a family to its true position in a system. The 

 principle as applied in the present case leads Dr. Hooker to 

 the conclusion that the nearest relatives of Balanophorece are 

 the Heloragece, a group itself, " consisting for the most part 

 of reduced forms of Onagrariece" or, more strictly speaking, 

 that the link which connects these plants with the higher 

 forms of vegetation is furnished by Gunnera. The qualifying- 

 phrase above is appropriate ; for it is hard to conceive of 

 Gunnera with its minute embryo as a reduced Onagracea, 

 while it is impossible to sever the cbain of evidence winch 

 binds the genus to Loudonia and Ilaloragis. Be this as it 

 may, Dr. Hooker has surely made a happy hit in seizing upon 

 Gunnera as the key to the true affinities of Balanophorece. 

 Of all the objections that may be urged against this approxi- 

 mation not the strongest, but rather the least valid, in our 

 opinion (so long as the question is one of alliance and not of 

 co-ordination), is that to be derived from the habit and the 

 imperfection of the foliar organs. Any type is liable to have 

 its parasitic phase, and this is generally a degraded one in 

 these respects ; the Gesneriaceous has it in Orbcmchece, which 

 it might with the greatest propriety include ; the Scrophula- 

 riaceous graduates insensibly into similar parasitic forms : the 

 Ericaceous has them in Monotropem ; and the Cornaceous 

 or Olacaceous degrades through Santalacece into Loran- 

 thacece. 



It is quite probable that our author would deny the degra- 

 dation in the latter case, judging from some points which he 

 makes when considering whether the group of Balanophorece, 

 " putting aside any consideration of its relationship with other 



