SCIENTIFIC AND TECHNICAL SOCIETIES. 
Scientific and Technical Societies. 
ROYAL SOCIETY OF VICTORIA. 
At the November meeting the following paper was read:— 
A Description of the Bracebridge Wilson Collection of Victorian Chitons, 
with Description of a New Species from New Zealand. By Edwin Ashby, 
F.L.S., M.B.0.U. 
This collection was made by the late Mr. J. Bracebridge Wilson, working in 
connexion with the Port Phillip Exploration Committee of the Royal Society, 
‘and was dealt with in a very able manner by Mr. EH. R. Sykes, B.A., F.Z.8., in 
the Proceedings of the Malakalogical Society in 1896. . : 
In view of more recent investigations by a number of earnest workers, it has _ 
been found necessary to alter some of Sykes’ identifications. Considering the 
comparatively small number of specimens, the collection is a most remarkable 
one, and contains an extraordinary percentage of rareties. In addition to the 
five species described by Sykes as new, the author notes four other species then 
undescribed. One of these, Callochiton rufus, Ashby, has hitherto been only 
known by a single type specimen dredged in South Australia. A new species of 
Lepidopleurus, from New Zealand, is also. described. 
Dr. J. M. Baldwin delivered a lecture on Application of Genetics to Plant 
Breeding. 
During the past twenty years activity has been displayed in plant breeding 
throughout the world. This activity is largely due to the re-discovery of 
Mendel’s work by De Vries, Correns, and Tschernak, the epoch making work of 
De Vries on the Mutation ‘Theory, and the stimulus given through the establish- 
ment of schools of genetics throughout the world. The problems of genetics are 
those which grow out of a study of the resemblances and differences in indivi- 
duals related by descent. There are four general lines of attacking the 
problems—(qa) the method of observation used by Darwin in marshalling evidence 
in favour of the evolution theory; (6) biometrical methods, employed with such 
success by Pearson;-(¢) cytological methods, which are primarily concerned with 
a study of cell mechanism; (d) experimental breeding, which involves the raising 
of pedigreed cultures of plants. From the last method have come many stimu- 
lating ideas of heredity and variation, including the Mendelian theory of 
heredity, the pure line theory of Johannsen, and the mutation theory of De 
Vries. One important result of this method of analysis is to demonstrate that 
the germinal material is made up of definite factors or units which stand in 
close relationship to the particular characters of the soma, and to demonstrate 
how these elements are transmitted from generation to generation. ‘The pure 
line theory and the mutation theory stand in close relationship to the Mendelian 
theory, because they may be interpreted in terms of the elements which con- 
stitute the germinal substance. Johannsen showed that the fluctuations pro- 
duced by differences in moisture, sunlight, and fertilizer received by the different 
individual plants, i.¢., fluctuations induced by the plants’ environment, were not 
inherited. They behaved exactly as the acquired characters of an animal which 
Weismann showed were not inherited. Variations among individuals of like 
germinal constitution is a response to external or internal conditions which are 
not reflected in the germinal substance, and such variations are of no consequence 
for the establishment of new hereditary characters. The mutation theory estab: 
lished the occurrence of occasional definite discontinuous changes in the germinal 
substance, in consequence of which new characters are added to the race. 
Mendelism has given us a plan of heredity, but the more intimate and funda- 
“mental knowledge of the material which is employed in the elaboration of the 
plan remain the task of cytological research. Genetics may be applied on the 
scientific side to formulate doctrines of evolution, and on the practical side to 
the production of improved races of plants. New and improved varieties may 
be. produced by selection or hybridization. While great improvement had been 
wrought in plants by selection, the main rédle of selection was to isolate the 
heritable variations which are so much rarer than the discontinuous fluctuations 
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