436 Moore. — Essential Similarity of Chromosome 
spermatogenetic cellular generation as being pre- or post- 
synaptic, as the case may be. 
Now the fundamental argument contained in Professor 
Strasburger’s paper is, that there exists a similar synapsis or 
rolling together of the chromosomes in the case of plants, and 
that this alone fulfils the physiological necessities of the case, 
the 4 Reductionstheilung,’ if it exists anywhere, being an adap- 
tation or an abnormality. 
As I have already pointed out, however, not only the exist- 
ence, but the universal existence of the 4 Reductionstheilung,’ 
as something superadded to the synapsis, or reduction in 
rest, is claimed by the author of the Germ-plasm as a logical 
necessity, arising from the premises of his theory. In fact, 
the 4 Reductionstheilung’ is a sine qua non in this theory, and 
enables us to understand why Dr. Haecker should speak of the 
reduction occurring in the prophase of heterotype divisions, 
as a pseudo-reduction, and why, on page ioo, while referring 
to the similar processes in plants, he should say, 4 I believe 
that by assuming such a fusion, the process of reduction is 
robbed of all theoretical significance, as far as such significance 
bears upon the theory of heredity,’ since by this he can only 
mean that the 4 Reductionstheilung,’ as such, is presupposed 
by the theory of heredity, and that any observations which 
discredit its universality are therefore probably unsound. 
The question immediately waiting solution then, is, does 
the 4 Reductionstheilung’ exist universally as a final stage in the 
formation of the sexual cells of plants and animals, or not ? 
According to vom Rath's description of the 4 Reductions- 
theilung ’ in Salamander (which, so far as I know, is the only 
case in which the process has hitherto been described in 
vertebrates), it is said to occur among those generations of 
spermatic cells which in amphibia follow the great spermatic 
heterotype division. It is, in fact, relegated to those singular 
and well-known mitoses with tetrapartite chromosomes, which 
were figured and described by Flemming 1 J as probably abnor- 
1 Arch, fiir Mikr. Anat., Bd. XXIX, p. 445, and Taf. XXV, Figs. 46-50. 
