1908] KILDAHL—PHYLLOCLADUS ALPINUS 345 
and states that there are eight to sixteen free nuclei. JAGER (13) 
found sixteen free nuclei in the proembryo of Taxus baccata; and 
CouLTeR and Lanp (9) found four free nuclei in 7 orreya taxtfolia. 
One of the older ovules showed a long suspensor and an embryo of a 
few cells buried near the base of the gametophyte (fig. 33), but it was 
impossible to make out its structure. 
Summary 
The microsporophyll has two abaxial sporangia and the micro- 
spores are shed on November 1 or before. 
Two prothallial cells are formed, the first of which is generally 
evanescent; sometimes both persist as free nuclei, the walls of both 
being evanescent. 
The mature microspore has usually four free nuclei, and occa- 
sionally five, 
The ovulate strobilus is borne on the phylloclad, and bears two to 
eight ovules, 
The ovule has two integuments; one thick and fleshy, the other 
(arillus) thin and leathery and persistent only at the base. They 
are free from the nucellus to its base, and contain no vascular strands. 
Microspores are found resting on the top of the nucellus on Novem- 
Ft, and occasionally pollen tubes-and archegonia are formed at 
this date. 
Pollen tubes are very numerous and pass in a comparatively 
Straight line through the nucellus to the archegonium. They smash 
the neck cells, if there are any, and empty their entire contents into the 
gg; the contents of one or more pollen tubes were found in an egg 
after the eight-nucleate stage of the proembryo. 
The body cell divides into two equal male cells just before dis- 
arge into the egg; and only one male cell functions. 
The archegonium is surrounded by a heavy jacket layer, consisting 
of multinucleate cells with large nuclei. Two neck cells are probably 
fo No ventral cell or nucleus was found, but the material does 
Not justify a definite statement as to its occurrence or not. 
The male cell is surrounded by a cytoplasmic sheath which, partly 
at least, Surrounds the fusion nucleus. 
At least eight free nuclei are formed by the proembryo before cell 
Walls are formed; and a long suspensor is developed. 
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