34 Hybridisation of Amphibians [January, 
probably never find an anatomical definition for generation, 
as in principle none is possible. 
If we consider that every point in our organism is in- 
fluenced both by the spermatozoon and the ovum whence 
we have originated, it is plain that generation presupposes 
the absolute intermixture of the substance of the spermato- 
zoon with that of the ovum. When, therefore, during the 
adt of generation (which lasts until the two cells have be- 
come one, — i.e., from the moment when the head of the 
spermatozoon comes in contadt with the yolk to the origin 
of the first segmentation nucleus), the matter of the 
spermatozoon is molecularly mixed with that of the ovum, 
this can scarcely be understood save on the supposition that 
the generative elements are, at least at certain points of 
time, in a state of liquid aggregation. The true germs may 
easily be chemical molecules of definite constitution. The 
spermatozoon must evidently surrender its inherent organ- 
isation in order to become an integrating and all-present 
part of the new organism, and the same holds good for the 
ovum. Necessarily there exists a moment of internal trans- 
position of the molecules, and doubtless in part of the 
atoms. During this stage of revolution there exists no 
organisation. Our readers may here be reminded of the 
suggestive fadt that when the larvse of certain Diptera pass 
into the state of pupae their muscles are resolved into a 
uniform semi-fluid mass. During the adt of generation, 
properly so called, we have neither cellular substance nor 
nucleus, but nascent protoplasm. That this view is corredt 
in principle can scarcely be doubted, though these processes 
are probably not completed simultaneously in all points of 
the generative mixture. 
The author sums up his views on this part of the subjedt 
in the following chemical, or perhaps metachemical, repre- 
sentation : — 
The chemical work in the molecule of living animal 
matter possesses its highest intensity in youth, and then 
decreases, becoming very small in age, and being extin- 
guished at death. The “ adtive ” molecules — those with 
free affinities — constantly decrease, whilst the closed mole- 
cules increase. Hence for the maintenance of life a reci- 
procal process must exist, for converting the closed 
molecules into open or adtive ones. The opening of the 
closed affinities of the germs is therefore the essence of 
generation. 
As every chemical readtion of two molecules liberates 
chemical affinities, and as eledtricity, heat, and light do the 
