94 BOTANICAL GAZETTE ‘[F 
the second prothallial nucleus, whether fragmented or not, & 
vinces me that this at least is normal, and that we have in Podo- 
carpus a case analogous in this respect to Ginkgo and 
Cycads. This view is further supported by the | presence in 
pollen tube, in the only three cases in which I was able to tol 
it throughout, of three small nuclei in addition to the body < 
or its products. Figs. rg and 76, sections from the same f 
tube, show a case of this kind. The absence of early sta 
the sprouting of the pollen tube makes a distinction Re! 
prothallial and stalk nucleus difficult, but their positions 
the designations given in the figures. There can be little ¢ 
as to the identity of the pollen-tube nucleus (7%, jig. fig. 16). 
Juranyi (1870) twice found two nuclei in the tip 
young pollen tube of Ceratozamia longifolia, but the | 
may have here resulted “from the abnormal conditions, 
_ tubes were sprouted on ripe pears. Arnoldi (1g00, 2) Hgu! 
extra nucleus in the pollen tube of Cephalotaxus Fortune, 
very recently Miss Ferguson (1go1, a) found two cases ' 
__ the pollen grain of Pinus Laricio still contained three nuc 
the tube nucleus had passed out.. In the case of Pin 
. probable explanation seems to be that the extra nucleus 
of the second prothallial cell, as in Podocarpus. , 
Pe erhaps. the persistence of one of the prothallial 
aS once common in all conifers; an ancient character whic 
<< generally suppressed, may occasionally appear. : 
- a reversion, and that the peculiarities of its pollen are 
acteristic for the species. Whether such is the cas¢ 
work can determine. - 
THE POLLEN TUBE. 
oe On June 26, the date of the first collection, ferti 
: ay taken place in the majority of cases, and © 
= body el etre pollen tubes were found. Fig. 72 illus 
eee — oaeged its vision, what is ssa th 
