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-© RECENT RESEARCHES IN THE DIATOMACEJF. 67 
special attention of my fellow-labourers to the observation of our author, 
that so partial an investigation cannot continue without injurious effec 
this T whi 
This arduous enterprise he entered on with full confidence of ultimate 
success, and aide a very extensive acquaintance with the literature of 
the subject. I wo ke occasion to recommend my fellow-labou 
meer. * The labour of acquiring a knowledge of the Danish language 
will be well requited by the profit and pleasure they cannot fail to derive 
from its perusal. 
A patient and careful examination of the several species of Diatomacee - 
in the direction indicated by Dr. Pfitzer, even in the hands of men much 
less competent than he is, can scarcely fail to contribute most, important 
additions to our knowledge on the subject. At the same time, there is 
reason to doubt that a more satisfactory system of classification than we 
cessful. . 
Deferring my remarks on the direct results of Dr. Pfitzer’s observations 
to my next paper, I shall now refer to two matters of interest noticed in 
the introduction. 
"he name Diatomacee has been used by nearly all the more recent au- 
thors to designate the group. Rabenhorst, in his more recent work, has 
adopted the name Diatomophycea, but in his former treatise used that of 
acee 
been so generally adopted by recent writers, but, on technieal grounds, 
Dr. Pfitzer's view is undoubtedly correct. 
The most interesting portion of the introduction is, perhaps, that in 
which the author sketches the gradual progress of knowledge regarding 
the true structure and development of the Diatomaceous frustule, from its 
first dawn to the present moment. The bivalve character of the frustule 
was known before adequate notice had been taken of the hoop, or connec- 
tive membrane, which binds the two valves of the frustule together. And 
even after the importance of this part of the frustule had been to some 
extent recognized, its true structure and its relation to the development of 
the plant were overlooked. 
Wallich in 1858 observed that in the case of Amphitetras Triceratium 
* A critical review of this book will be found in Journ. Bot. 1864, "m 321-323. 
F 
