1892.] Heredity and the Germ- Cells. 669 
have found how untenable is the alternative theory offered to 
us by Weismann, that it is solely natural selection or the sur- 
vival of the fittest which 
“. . . shapes our ends, 
Rough-hew them as we will.” 
At the same time Weismann’s conception of a continuity of 
germinal protoplasm, which we have found to consist in chro- 
matin plus archoplasm, helps us over many of the phenomena 
of heredity, especially on the retrogressive side, and if it were 
not that we must also account for progressive and definite 
transformation in heredity, we might credit the distinguished 
Freiburg naturalist with having loosed the Gordian knot. 
In summing up, the order of treatment followed in the lec- 
tures may be reversed, and we can begin with the germ-cells, 
and condense the more or less ascertained facts. 
the Germ-cells—1. The material substance of hereditary 
transmission is the highly coloring protoplasm, or chromatin, 
in the nucleus of the germ-cells, probably connected with a 
certain form of archoplasm, or dynamic protoplasm, outside of 
the nucleus. 
2. Before conjugation and fertilization the hereditary sub- 
stance of both the male and female cells is reduced to one- 
half that found in a typical cell. The substance is, however, 
first doubled and then quartered, the meaning of which pro- 
cess is not understood. 
3 There is a difference of opinion as to whether the pater- 
nal and maternal hereditary substances, are fused or lie side 
by side during fertilization, also as to how the substance is 
distributed through the tissues, during individual growth, 
whether en masse or by qualitative distribution. 
Heredity—4. No form of physical connection between the 
germ-cells and body-cellg is known, but the facts of heredity 
seem to render such a connection theoretically necessary. 
Several classes of facts witnessed in reproduction seem to 
‘support this theory. 
