Dr Gardiner, On the mode of formation, etc. 
209 
On the mode of formation of the initial cell-wall, the genesis 
and neogenesis of the connecting threads, and the method of con- 
nection of living tissue cells. By Walter Gardiner, Sc.D., F.R.S., 
Clare College. 
[Bead 11 February 1907.] 
Having summarised the existing theories as to the structure of 
the “ initial-wall ” of plant cells, and the current view expressed by 
Strasburger as to the development of connecting threads, the 
author stated that his own observations appear to prove that the 
above views are inadmissible. 
His observations appear to show that neither the cell-plate 
nor the initial-wall — which he proposes to call the “ cleavage- 
wall ” — can be regarded as homogeneous membranes; but that at 
the period of division of the cell when the cleavage- wall secreted 
by the cell-plate is in process of deposition, the cell-plate is still 
traversed by persistent fibrillar remains. He believes that the 
cleavage-wall is either perforated by intact fibre nodes or contains 
within its structure bisected fibre nodes separated by cleavage- 
wall membrane. In the opinion of the author the fibre nodes or 
semi-nodes (whichever the case may ultimately turn out to be) are 
the rudiments or initials of the developing connecting threads, of 
which the nodes of the several fibres are believed to form the 
“loci.” Initial boundary-walls, e.g. those of eggs, spores, etc., 
probably behave during development like cleavage-walls and may 
for this purpose be theoretically regarded as free cleavage half-walls. 
The author expressed his views on what he believed to be the 
fundamental significance of the cytoplasmic fibres in relation to 
mitosis, and urged that all fibres such as supporting fibres, traction 
fibres, general connecting fibres, and those of suns and asters are in 
reality homologous and (excepting perhaps traction fibres) may be, 
and probably are, capable of making provision for the formation of 
“ loci ” of connecting threads. As to the fibres generally he regards 
them as being largely of the nature of live scaffoldings which 
constitute the machinery for mitotic evolutions, cell- wall develop- 
ment, or other matters of cellular urgency. The function of the 
cell-plate is also largely mechanical in that it forms a firm 
“ supporting disk ” for the fibres ; holding them in position against 
obvious strain, and making possible the assumption of the spindle 
figures characteristic of mitosis. 
Connection during “ sliding growth ” is explicable, if it be 
admitted that there are two single walls, each bearing threads, 
which latter may unite or fail to do so, on the “hit and miss” 
