Miyake, The development of the gametophytes etc. 
15 
Strasburg er (1884) bas noticed tbe starcb-sbeatb around 
tbe fusing uuclei of Juniperus and expressed a surprise at the 
sudden appearance of starch, as he has not found any starch in 
tbe sperm-cell, while tbe pollen-tube contains yery little starcb at 
tbe time of fertilization. Later students of tbe Cupressineae 
(Lawson. 1907; Xoren, 1907) bave also observed tbe presence 
of tbe starcb-sbeatb. except Land (1902) wbo makes no mention 
about it in Thuja. Tbe presence of starcb in tbe sperm-cells 
were mentioned by Xoren in Juniperus and by Lawson in 
Libocedrus. Taxodium , Cryptomeria and Cunninghamia bare tben 
tbese points in common witb tbe Cupressineae. 
Tbe fusing nuclei are usually found at tbe center of tbe egg. 
occupying tbe cavity of tbe yacuole, into wbicb tbey bave probably 
dropped in alter botb nuclei came in contact. Tbey may not fill 
up tbe entire space of tbe yacuole. and tbere is often a space left 
between tbem and tbe rest of tbe egg-cytoplasm (figs. 89. 113). 
Tbis space is. however, gradually filled up by tbe surrounding 
cytoplasm. and almost disappear at tbe time of tbe first spindle- 
formation. 
Tbe outline of tbe female and male nuclei remains distinct 
until tbe fusing nuclei prepare tbemselyes for diyision. It bas been 
reported tbat in Taxodium (Coker, 1903) and Taxus (Jäger. 
1899) tbe fertilized nucleus passes down to tbe base of tbe egg 
before tbe first diyision occurs. Tbis is eyidently not tbe case in 
Cunninghamia , for tbe first division-figure was always found at or 
near tbe center of tbe egg. just about tbe point where tbe fer¬ 
tilized nucleus is usually located (fig. 114). Most inyestigators of 
tbe Coniferae agree tbat tbe first diyision of tbe fertilized nucleus 
occurs near tbe center of tbe egg. So it was found by Lawson 
to be tbe case in Cryptomeria and seyeral other members of tbe 
Cupressineae . Arnoldi (1900), on tbe other band, States tbat in 
Sequoia tbe first diyision takes place at tbe base of tbe egg, but 
tbe fact was not confirmed by Lawson (1904a). 
Embryo-formation. 
Tbe fertilized nucleus soon prepares for diyision, while tbe 
outline of eacb sexual nuclei is still distinct. Tbe nuclear mem- 
brane becomes indistinct and tbe spindle originates at tbe point 
where tbe walls of two nuclei meet. Tbe process of diyision does 
not seem to differ mucb front tbat obseiwed in other Conifers. 
Miss Ferguson (1901, 1904) made a yery minute study of tbe 
diyision in Pinus and tbe results of her study can, in tbe main, 
be also applied to Cunninghamia. An early stage in tbe spindle- 
formation of Cunninghamia is sbown in fig. 91 wbicb resembles 
Miss Fergusons (1901) fig. 56 witb tbe exception tbat tbe latter 
bas no starcb-sbeatb. Tbe sindle is intra-nuclear and seems to 
originate as a multipolar structure. Tbe cbromosomes are found 
‘in two groups and eacb group bas eyidently deriyed front one of 
tbe sexual nuclei. 
