34 
Beck, on an Improved Growing Cell. 
I am, moreover, in a position now to supply a limited 
number of living specimens to any one who is anxious or 
willing to investigate the subject, and I can at any rate 
promise a certainty in the supply of food, for I find that they 
are perfectly satisfied with the common cheese-mite. 
A further investigation, therefore, into this subject, only 
requires the expenditure of a moderate amount of time and 
care, and the importance of agamic reproduction may be 
estimated by the attention it has already received from the 
most scientific naturalists. 
An Improved Growing Cell. 
By Richard Beck. 
(Read December 13th, 1865.) 
I WAS shown by Mr. Suffolk at our last meeting a new 
growing trough contrived by Mr. Smith, of Kenyon College^ 
U.S. A description of this piece of apparatus has been given 
in ^ Silliman's American Journal of Science,'' September, 
1865, and it has also been republished in the last November 
number of the ' Annals of Natural History.^ 
I think every one will admit that the principle on which 
the growing trough is contrived is very ingenious, and that it 
will prove of no little importance in many microscopical 
investigations. 
The few suggestions which I shall make refer to the con- 
struction only, and to make therli intelligible I must first 
quote Mr. Smithes description which is as follows : — 
The whole slide, as I have constructed it, is a trifle more 
than -^th of an inch in thickness. It consists of two rect- 
angular glass plates, 3x2 inches, and about Vt*^^ of mch. 
thick, separated by thin strips of glass of the same thickness, 
cemented to the interior opposed faces, as shown in the 
figure. 
" The upper plate has a small hole, a, drilled through it. 
One corner of the upper glass is removed, as at and a 
small strip of glass cemented at c serves to prevent the thin 
glass cover placed over the edge from sliding. To use the 
slide, fill the space between the two plates with clean water^ 
introduced at b by means of a pipette, and also place a drop 
on a to remove the air. The object being put on the top of 
the slide and wetted, is now to be covered with a large square 
of thin glass, c, at the same time covering the hole, a. The 
slide can now be placed upright, or in any position, as no 
water can escape. It is, in fact, only a new application of 
