Io 
Hbstract of Proceedings. 
1905. 
$9 $9405 
GENERAL MEETINGS. 
Friday, January 6th. Sir Samuel Wilks, Bt., M.D., F.R.S. 
President, in the Chair. 
Professor Marcus Hartog, D.Sc., gave a lecture on ‘‘ The 
End and Beginning of Individuality, as shown in the Living 
Cell,’’ illustrated with lantern slides. The lecturer remarked 
that all living organisms grow, but any body that increases in 
size and retains the same form reduces the surface relative to 
bulk. To take a simple case, a cube one inch long has a bulk 
of one cubic inch, and a surface of six square inches; a cube two 
inches long has a surface of twenty-four square inches and a bulk 
of eight cubic inches, that is, its surface is only three square inches 
per cubic inch of bulk—it has only half the relative surface of 
the inch cube. Hence organisms cannot increase beyond a certain 
limit in size. All organisms are built up of units called cells, 
and the same law of limit applies to them. When they attain a 
certain size they divide into two or more. The original cell is 
called the mother-cell, and the two new ones are the daughter- 
cells. In this case the individuality of the parent is merged into 
' that of the two offspring. A cell consists of a body of so-called 
“‘cytoplasm,”’ and a central mass, the “nucleus.” There are 
two modes in which anything can be halved. You may “ halve 
your purse”’ by seeing the amount and giving half that amount 
to your friend, or you may see how many coins of each denomina- 
tion you have, and divide these into equal shares—the latter is 
called “‘ partitive’’ or “distributive” division. The cytoplasm 
of the cell divides after the first mode, the nucleus after the second. 
The lecturer then explained with diagrams the mode in which 
this division takes place in the two cases, that of the cytoplasm 
being by simple constriction, that of the nucleus being too com- 
plicated to be intelligible without figures. To effect the distributive 
nuclear division a curious ‘‘ field of force” appears in the cyto- 
plasm, he said, which may be paralleled by that of two isolated 
poles of magnetic or electrostatic force. This was shown by 
or aed 
