298 Transactions. — Botany. 



European species or the discovery of new ones. And yet, were it not for 

 tlie extreme minuteness of the plants composing this family (the largest of 

 which is only visible to the naked eye under certain Hghts), I venture to 

 think that the elegance of form and varied grace which distinguish them 

 would have drawn universal consideration to them. Unfortunately, they 

 cannot be cultivated, and occurring as they do in wayside ponds and 

 amongst masses of water-weeds their very existence is generally despised 

 and probably almost unknown. 



I have had occasion already, when treating of the New Zealand Coccidas,* 

 to remark upon the difficulty experienced here in studying the different 

 classes of animals or plants, a difficulty arising chiefly from the want of books 

 of reference. Geographical obstacles to communication between various parts 

 of the colony stand much in our way, but these might be got over. But 

 in examining any species it is imperative to know, as far as possible, 

 whether it has ever been referred to elsewhere or by anyone else, and to be 

 able, at least approximately, to determine its affinities. For this purpose 

 easy access to works of reference is indispensable if satisfactory knowledge 

 is aimed at ; and this is just what is wanting here. The difficulty is still 

 more enhanced in the case of such objects as the Desmidiese, because it is 

 quite impossible to keep them for any length of time in their original state : 

 so that often, before comparison could be made with species described as 

 existing elsewhere, the specimens woiild be ruined and lost. And drawings, 

 let them be ever so apparently accurate, cannot, until all specific characters 

 are thoroughly made out, supply the place of the object itself, at least for 

 purposes of study. 



The Desmidiese are, to students in Christchurch, particularly subject to 

 this difficulty. The standard work on them, Ealfs' "British Desmidiese," 

 is more than thirty years old, and microscopic investigation has made 

 immense strides since its publication. Descriptions, references, and some- 

 times figures, are scattered in papers by different authors in such periodicals 

 as the " Journal of Microscopical Science," the " Annals and Magazine of 

 Natural History," the " Zoolog-Botanische Gesellschaft" of Vienna, etc. 

 And, independently of the difficulty of searching for and collating these 

 disjecta membra, it is the case, unfortunately, that in Christchurch the series 

 of such periodicals is much broken, confused, and difficult of access. 

 Ehrenberg's great work on the Infusoria (a copy of which is, I believe, 

 shortly to be added to our library) is still older than that of Ralfs. It fol- 

 lows from what I have said that, in investigating and describing any such 

 family as that of the Desmidiese, the student, even after all his pains, has to 



* " Trans. N. Z. Inst.," Vol. XII., p. 291. 



