1903] GAMETOPHYTES AND EMBRYO OF TAXODIUM 123 
egg, and may be long distinguished as they slowly disorganize 
( figs. 104, 110). 
The functional sperm cell in its course to the egg nucleus is 
shown in figs. roo and roz. Its protoplasm becomes intimately 
connected with that of the egg, but its identity is not lost at any 
stage. The starch sheath still remains in close contact with the 
sperm nucleus, and as its boundary touches the wall of the female 
nucleus it spreads around it more and more, while the sperm 
nucleus in its center finally comes in contact with the nucleus of 
the egg ( fig. ro2). This starch sheath of the sperm nucleus 
furnishes the sheath which is characteristic of the fusion nucleus. 
Strasburger has several times spoken of the sudden appear- 
ance of starch in the fertilized egg of the Cupresseae. In his 
Neue Untersuchungen (1884) he expresses surprise at this, because, 
as he says, the pollen tube here contains very little starch before 
fertilization. His description in Juniperus of the starch sheath 
appearing around the fusion nucleus immediately after its forma- 
tion and the subsequent behavior of the two may be applied 
almost word for word to Taxodium. It seems probable, there- 
fore, that starch may yet be found in the male cells of the 
Cupresseae. 
The sperm nucleus before contact with the female has the 
same character as was noticed in the pollen tube. It is difficult 
to distinguish it from the protoplasm around it, but a central 
nucleolus and a scarce reticulum may be made out in the dense 
substance that completely fills the nucleus. When the sperm 
cell enters the egg its nucleus is not more than a fifth the diame- 
ter of the egg nucleus (fig. roo), but during its course to the 
latter the sperm nucleus enlarges somewhat (fig. roz), and just 
after contact the diameter of the two nuclei is about as one to 
two. The male protoplasm, with its inclosed starch, now com- 
pletely infolds the egg nucleus until it becomes evenly distribu- 
ted around it ( figs. ro2, 103, 105). The structure of the sperm 
nucleus begins to change immediately on contact with the egg 
nucleus. The linin substance becomes arranged into a reticu- 
lum staining deep blue with gentian, while the nucleolus seems 
to break up into a number of smaller granules which lie more or 
