Dec., 1913 . The Queensland Naturalist. 269 
from one generation to the next, while the body which bears 
and nourishes the germ-cells is, in a certain sense only an 
outgrowth from one of them. 
The ultimate constituents of the germ-plasm are the 
Biophores, each of these being a group of molecules, on 
which the phenomena of life depend. These Biophores, 
unlimited in kind, constitute all protoplasm, and each kind 
corresponds to a different part of a cell. They are grouped 
together to form “ determinants,” which are the entities, 
deciding the nature of any particular kind of cell, any 
particular structural character, or function. In the ceil 
nucleus they are grouped together to form “ ids,” and the 
chromosomes of the cell nucleus are called ” idants.” The 
cause of each determinant reaching its proper place in the 
body depends on the fact, that it takes up a definite position 
in the id of the germ-plasm. Every independently variable 
character is represented in the germ-plasm by a determinant. 
Each idant is made up of a full set of ids, determinants, and 
biophores. 
The mode of reproduction of the higher animals is 
bisexual, where one germ- cell unites with another. As 
under Weismann's views each chromosome, or idant, of 
egg or sperm contains the full set of ids, etc., in fertilisation 
these two are mingled. In the development of the fertilised 
egg, it is its composition, due to this mingling of the con- 
stituents, derived from two different ancestral sources, which 
determines everything in the constitution of the resulting 
individual. The development is a process of unfolding, with 
preformation, each different part, or characteristic, being 
present in the fertilised ovum, and its development is pre- 
destined. and he rejects the theory of the gradual adding of 
part to part — or Epigenesis. 
Amphimixis, the term used by Weismann for this 
mingling, is held to be the uniting of the hereditary influences 
of two individuals. The resulting organism must, therefore, 
take on traits of both parents, while the combination of the 
ids from each parent, which are dissimilar through forming 
new combinations, is the cause of difference from the 
parental forms and the cause of variation. It is held to in- 
crease the capacity for adaptation of the organism to its 
surroundings, because by it, the simultaneous adaptation 
of many parts is possible, and by means of ” germinal selection 
fosters the elements favouring a progressive variation, and 
eliminating unfavourable tendencies.” 
The theory is, of course, largely hypothetical. There 
is no proof thatThe development takes place as he states. It 
is only the chromosomes (idants) which are visible under the 
microscope : ids and biophores are a pure mental conception. 
Their existence remains to be proved by experiment and 
research into the structure of the cell. 
