554 
Gibbs. — On the Development of the 
It may possibly have this secondary result, as the berry-like swelling 
and sweet cell-sap persist to maturity ; but such a result can hardly be described 
as a function, it is in fact incidental. When a modification sets in at so early 
a stage, and is so gradual in its accomplishment, it shows the initial cause 
must be more fundamental in character than a merely secondary result 
would demand, and it is more probably correlated with the function of the 
nutrition of the young ovule, as previously suggested. 
The ground under the tree from which these strobili were collected 
was strewn with the Yew-like berries, and many were put up in formalin, 
both from the ground and from the tree, under the impression that they had 
been shed at maturity, but all were subsequently found to be in the pre- 
fertilization stage, as far as could be judged from the contracted prothallia. 
Oliver, in a paper on the ovules of the older Gymnosperms ( 37 , p. 455), 
discusses the fact that all the seeds of these plants preserved are in the stage 
just preceding fertilization, only occasionally being met with in an earlier 
state. He says : 
‘ In the course of evolution, probably, the time of banding the integu- 
ment was postponed till embryonic changes had set in, so that well-marked 
ovular or seed phases became very recognizable ; but in the Palaeozoic 
seeds known to us, such a distinction can hardly be drawn. In referring to 
them the term seed is usually employed, though in recent Gymnosperms the 
corresponding stage would be called an unfertilized ovule. This usage in 
terminology has doubtless arisen from the appearance of maturity which 
their integumentary tissues present, a maturity which seems to preclude all 
possibility of subsequent expansion.’ 
The latter sentence might equally well have been written of the same 
stage in Podocarpus. Merely some enlargement in growth, progressive 
lignification of the tissue of the mesophyll and integument, and the loss of 
function in the resin canals, which apparently coincides with the cession 
of further vegetative growth, are the only vegetative features in the em- 
bryonic stages in these strobili, the ovuliferous scale being fully developed 
for protective purposes by the pre-fertilization stage. 
Coulter and Chamberlain ( 18 , p. 47) consider it possible that the 
Palaeozoic seed matured in developing a testa before fertilization, but 
becoming detached after pollination, developed a proembryo which sub- 
sequently aborted. Scott, in reviewing the above work ( 47 , p. 171) in 
‘Nature’, says: ‘The interesting question of the constant absence of an 
embryo in all Palaeozoic seeds hitherto investigated is discussed. This has 
been regarded as the normal condition, the development of the embryo not 
having begun until the seeds were shed, and then having passed over at 
once into germination. The author inclines to the view that all Palaeozoic 
seeds investigated were abortive, having been shed prematurely. The fact 
that nearly all the seeds observed were in the same stage of development, 
