M3 
Spore Formation in Torreya californica. 
surrounding cells are starch free. The nucellus does not as a rule 
shew a very definite arrangement of the cells in linear series ; the 
most distinct indications of such an arrangement occur in a section 
■cut at right angles to the plane in which the ovules lie. The 
grouping of the surrounding cells is shewn in Fig. 23. The mother 
cell is not accompanied by a large-celled tapetum, such as that 
found by Coker in Taxodium, but the cells immediately round it 
are distinguished by dense contents and rather conspicuous and 
active looking nuclei. The m’other-cell was much further advanced 
this year than in 1902, for among the material collected on May 
17th, there were some mother-cells in synapsis (Fig. 25). This 
stage was not reached in 1902 until three weeks later, Coker 1 
describes and figures synapsis in the mother-cell of Taxodium 
at a corresponding stage, and Juel- figures what appears to he a 
condition of rather incomplete synapsis in the embryo-sac of Larix 
sibirica. The majority of the embryo-sac mother-cells in synapsis 
which I have seen had been fixed in alcohol. I have only examined 
one mother-cell in this condition fixed in weak Flemming and one 
fixed in chromic acid. In both these cases I have found a delicate 
brush of fibrils in the protoplasm at the basal end of the cell 
(Fig. 25). So I should imagine that its absence in the alcohol 
material was due to imperfect preservation. In the case of Larix 
sibirica Juel describes a fibrous structure in the protoplasm 
occurring as a rule at the upper end, and once at the base of the 
embryo-sac mother-cell. But it differs from the structure in Torreya 
to which I refer, in not occurring until the stage when the nuclear 
thread is beaded, and also in being in the form of a meshwork and 
not a brush. In Taxodium Coker 3 mentions the occurrence of 
denser fibrous areas which he regards as of the same nature as 
those in Larix, but in his figures they appear to be rather granular 
than fibrous, and hence differ still further from the appearances in 
Torreya. When the embryo-sac mother-cell is in synapsis it is 
packed with starch, which is absent in the surrounding cells. In 
material collected on June 1st, 1904, which shewed the mother- 
cells at various stages of development, three of them had nuclei with 
beaded threads, and so were probably at a stage of development 
intermediate between the synapis and the reduction spindle (Fig. 
26). On June 24th, 1902, a fortnight after the occurrence of the 
1 loc. cit. 
2 H. O. Juel. Beitriige zur Kenntniss tier Tetradentheilung. 
Pringsheims Jahrb., Bd. 35, 1900 p. 626. 
3 loc. cit. 
