300 Transaction^.— Botany. 



knowledge is reliable, so that in the succeeding portions of 

 the paper no ill-considered generalizations may be indulged in. 



Unfortunately, neither Harvey nor Agardh ever visited 

 New Zealand, and consequently they have only seen our 

 plants in the dried condition ; but the latter, doubtless in- 

 heriting his father's rich collections, and having received dupli- 

 cate types of most of the species described throughout the 

 century, has had a far wider range of specimens to work 

 upon than Harvey, who, however, had examined the 

 Australian marine Alga? in the living condition during a stay 

 •of some months there. Agardh, again, has been for many a 

 year, and still is, the chief living authority on the morphology 

 of the Alga?, and his list undoubtedly represents a far closer 

 approach to accuracy than that of the Handbook. It must be 

 noted also that it is in no way a compilation, as the other was. 

 He has only inserted in it a few species not collected by 

 Dr. Berggren, and these upon the best authority. It may 

 be fairly assumed, under these circumstances, that very 

 nearly all of the species enumerated in it are genuine, and 

 inhabitants of our shores. On the other hand, it is quite 

 impossible to say how many of the fifty species excluded may 

 again be found here. Against many of them the prima facie 

 evidence is strong. Amongst them are no less than eleven 

 species of Polysiphonia. This is the largest and most difficult 

 genus of Bhodophycece to discriminate, and there must always 

 be much uncertainty as to the exact delimitation of its species. 

 Another dozen have only been collected at the Auckland 

 Islands, and the majority not at all since D'Urville's expedi- 

 tion. Taking all things into consideration, it is probably 

 correct to assume that at least two-thirds of Agardh's 

 " species excludendae " have been rightly thrown out. On 

 the other hand, we may be satisfied that those species which 

 have survived the criticisms of two such competent judges as 

 Dr. Harvey and Professor Agardh, working in complete inde- 

 pendence of each other, are genuine. Undoubtedly a con- 

 siderable number of Bhodopkycece still remain to be discovered 

 — in fact, I have now some undescribed species. Even in 

 Britain itself fresh indigenous species are still being brought to 

 light, and certain kinds of Alga5 {e.g., shell-boring species) 

 have not even been looked for here. 



The collection sent Home by Professor Parker included 

 fifty-one species, of which one only (Bhodocorton parkeri, 

 Gibson) is new to science. Professor Harvey Gibson seems 

 to have fallen into a strange mistake with regard to the 

 habitat of this plant. He states that he obtained it " growing 

 at the base of a cluster of molluscau (?) eggs." : Thanks to 



* "Journal of Botany," June, 1893. p. 163. 



