448 Beard and Murray. — Reproduction in A nimals 
On the Phenomena of Reproduction in 
Animals and Plants. 
Reducing Division in Metazoan Reproduction. 
BY 
J. BEARD & J. A. MURRAY, B.Sc. 
A REDUCING division in itself, apart from the previous 
history of the cell in which it occurs, or of the ancestors 
of that cell, is of course unintelligible. It is needful to 
enquire in both animal and plant how from this past history 
the reduction was rendered imperative. It is, as Strasburger 
has insisted, ‘ a return to the original generation from which, 
after it had attained sexual differentiation, offspring was 
developed having a double number of chromosomes V Theo- 
retically it is the undoing of the displacement of balance 
among the ‘ organs ’ of a cell due to duplication at a previous 
conjugation 1 2 . 
In the researches of recent years on the mode in which 
the reduction takes place in oogenesis and spermatogenesis 
the burning question has been whether it was by a longitu- 
dinal, or by a transverse, fission of chromosomes. A longitu- 
dinal division is proved to be incapable of effecting this, 
because it is the mode in which any ordinary cell-division 
is brought to pass. And the failure of the chromosomes to 
1 Loc. cit, p. 289. 
2 The term ‘ conjugation ’ is used to represent generally the union of two nuclei 
whether in Protozoan or Metazoan. The final act of union is fundamentally the 
same in both cases, as will appear subsequently. 
