470 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 
development of the Limpet, was also shown. A cordial vote of 
thanks was accorded to Dr. Gemmill and Mr. Alex. Gray, curator 
of the Millport Marine Station, who assisted him. There was a 
large attendance of members and friends. 
28rH Frpruary, 1899. 
Mr. Robert Kidston, F.R.S.E., F.G.8., President, in the chair. 
Messrs. Robert Garry, 2 Hill Street, Garnethill ; Alexander 
Gray, Marine Station, Millport ; Robert Henderson, 12 Arma- 
dale Street; and Alfred J. Steven, 54 Albert Drive, Pollok- 
shields, were elected as Ordinary Members. 
Mr. James Rankin, M.B., C.M., B.Sc., delivered a lecture on 
“Physiology as a Factor in Evolution,” which was illustrated by 
lantern slides. The lecturer dealt with the theories of Lamarck, 
Darwin, and Weismann, expressing himself favourably concerning 
that of Lamarck, who held, inter alia, that new organs appeared 
in response to a “new need or want which continued to be felt,” 
and also in favour of the hereditary transmission of acquired 
characters He reviewed at length Weismann’s theory of the 
“continuity of the germ-plasm,” and quoted evidence from more 
recent observation and experiment which showed that the increase 
of our knowledge of the behaviour of cells under certain conditions 
tended to discredit that hypothesis. He stated that while it was 
difficult to prove the transmission of acquired morphological 
characters, yet in the phenomenon of instinct, or hereditary 
memory, in the lower animals, we had an example of the trans- 
mission of acquired mental traits. Dr. Rankin pointed out that 
in unicellular animals all the physiological functions necessary 
to life were carried on, and that these differed in degree only, not 
in kind, from those of the highest animals, and also that in all 
probability the qualities shown by the highest animals were 
present, at least potentially, in the lowest. There is an evolution 
of the cell as well as of the individual, and in the lowest groups of 
animals many of the cells remained in an indifferent condition, 
and were thus extremely plastic, responding readily to physiologi- 
cal pressure from within and to changes in external conditions. 
To this plasticity of the cells, to physiological necessity, and to 
the influence of surroundings the lecturer attributed the radial 

