34 
The President's Address. 
form agrees witli that of tliree other members of the veget- 
able kingdom. 
At the same meetings Dr.Wallich, in a paper, entered into 
a discussion on the structure of the diatom valve ; believing, 
from his observations, that the growth of the valve ceases 
either at or shortly after its liberation from the parent. 
That, subsequently, no change in shape occurs in the 
siliceous valve except at its margins. That the mark- 
ings are circular, and arranged determinately according to 
species ; the figure being dependent upon forces occurring 
during its connection with the parent frustule ; the size and 
relative fineness of markings depending upon the condition 
of the frustule while in the stage of generation. As to 
the gelatinous envelope, its growth may probably go on in- 
definitely. 
The next paper relates to the zoophyte division of the 
animal kingdom. 
Professor Allman described, in a paper read 14th March, 
1860, a new genus of Lucernariidse, Carduella, identical 
with the species L. cyathiformis of Sars, but differing from 
the true Lucernariidse in the margin of the circular disc not 
being produced into the rays, the tentacles not springing from 
the edge of the cup, and in these being situated in a single circle. 
From a careful description of its anatomy, he believes it 
to represent a true hjdrozoan type, notwithstanding a resem- 
blance to the actinozoan,in the presence of the vertical lamellas 
connecting the stomach with the outer wall of the animal. 
The papers relating to the improvement in the microscope 
itself, and in the apparatus connected with it, have been, 
during the last year, more numerous than in any preceding 
one. Thus, there have been two on the Binocular form, by 
Mr. Wenham ; one on a Portable Field or Clinical Micro- 
scope, by Dr. Lionel Beale and another on a Dissecting 
Instrument, by Mr. James Smith. All these are fully de- 
scribed and illustrated in the ' Transactions,^ and are worthy 
of the greatest attention from their being the contrivances of 
men qualified in every possible way to show to the uninitiated 
w^hat is truly good and useful. Mr. Wenham^s invention, 
however, is one which requires more than a passing notice, 
as it is likely to prove of greater use to the observer 
than any other form of instrument which has yet been 
brought before the notice of the members of this Society; 
and glad should I be if the limits of this address would 
allow me to enter fully into some of its advantages. 
The next duty I have to perform is a painful one, viz., to 
remind you that although our little community scarcely 
