160 NATURAL SCIENCE. FEB., 1893. 
several of the best foreign Diatomists, who likewise failed to refer me to any 
previous description. Mr. Hogg and Mr. Minchin dealt with generalities. I should 
be glad to have a reference to any paper where these pseudopodia have been 
described. 
Secondly, I have found these diatoms with the pseudopodia in almost every bit 
of water—whether pond or stream—in the South of England, where I have looked 
for them. They occur in many places in London and the suburbs, and from 
Yarmouth to Sheerness, Eastbourne and Wiltshire. 
I advise my critics to take the trouble to get some of these diatoms and study 
the phenomena for themselves. If they will do so, I do not think we shall hear 
much more about either opinions, processes, or old discoveries. 
J. G. GRENFELL. 
[I am much surprised to find Mr. Grenfell including me among his “‘ critics,” 
with regard to the pseudopodia of diatoms. I do not profess in any way to be an 
authority on the subject, and the criticism which Mr. Grenfell kindly attributes to 
me was quoted word for word from Mr. Jabez Hogg. It was Mr. Hogg, not I, who 
asserted that the discovery of these so-called pseudopodia was a very old one, and 
that they have often been described. Mr. Grenfell seems to have overlooked the 
inverted commas in which these statements are placed. My only object was to place 
before English readers an account of Professor Biitschli’s researches upon the move- 
ment of diatoms, and to point out that ‘‘any form of pseudopodia is quite inade- 
quate and unnecessary to explain’’ the phenomena observed by him, without, 
however, expressing any opinion of my own as to the existence or nature of these 
so-called pseudopodia. 
E. A. MINCHIN.] 
PAL-EONTOGRAPHICAL SOCIETY. 
THE attention of the Council of the Palazontographical Society having been 
called to a paragraph in your January number, in which you wrote, ‘‘In the case 
of several of these monographs, announced as in preparation, we believe the state- 
ment is false, and that members of the Council are aware of the fact,’’ I am directed 
to state that all these monographs have beer promised, and that the promises have 
not been withdrawn. Tuos. WILTSHIRE, Secretary. 
[Promises are fickle. We have already proved the accuracy of our assertion 
in the case of two announcements, and the Secretary might be profitably ‘ directed ” 
to make further enquiries. The continued official repetition of promises, which are 
well known to be valueless, prevents other paleontologists from undertaking works 
that are much wanted.—ED. | 


TO CORKESEON DENTS. 
N.B.— CHANGE OF ADDRESS. 
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H. Uttyett (Folkestone).—The wingless bird referred to is not a species of 
Apteryx, but the well-known Weka Rail (Ocydvomus australis). Examples of this 
common New Zealand Bird can generally be seen in the aviaries at the Zoological 
Gardens in London. 
