200 Farmer and Digby.—On the Oy to logical Features exhibited by 
connexion is pulled apart, and the two nuclei thus become completely free 
from each other, and the cell-plate is formed across the intervening cyto¬ 
plasm. The final division of the spore mother-cell may also take place in 
the same manner (Fig. 21). The whole process is strikingly like that 
described for hybrid sorts of Syringa ( 5 . chinensis ) by Juel, 1 whose account 
was confirmed by Tischler, and, as will be seen, it also reappears in the 
hybrid P. Schneideri. But its occurrence is evidently not dependent on 
hybridity, but probably on a disturbance of the normal intracellular pro¬ 
cesses such as may indeed be brought about by hybridization, but which 
may also be connected with more proximate nutritional disturbance, 
whether produced by unfavourable environment 2 or by less obvious causes 
such as are associated with the formation of a ‘ sport as in the present 
instance. For there can hardly be any question of hybrid origin here ; the 
fern was found growing wild, and, besides, there is no other species which 
seems likely to have contributed to produce its peculiarities, and more¬ 
over the type species has long been known to be subject to sporting. 
Polypodium Schneideri. 
This fern is of large and somewhat robust habit. In this respect 
it recalls the P. aureum parent, although, except in some of the ‘ reverted ’ 
leaves, there is otherwise no very close resemblance between the two plants. 
In the laciniate foliage it is like a very vigorous form of P. vulg. elegantis- 
simum . Perhaps it is even still more like the variety known as cambrica. 
As we have already stated, the ‘ reverted ’ parts of the fronds may recall 
the appearance of either a gigantic polypody leaf, though in the wavy edge, 
and especially in the glaucous tinge, it approaches more nearly to the 
aureum type. 
Sporangia are freely produced both on the normal and on the £ reverted ’ 
leaves. The cells of the sporangia resemble the elegantissimum parent 
rather than the aureum type in their large size, a feature in which, as will 
be remembered, the two parents are dissimilar. Fertile spores have never 
been obtained, either by ourselves or, so far as we have been able to ascer¬ 
tain, by others ; the sporangial contents often die away at an early stage of 
development, and when this occurs the entire sporangium may degenerate, 
so that even the basal cell situated at the surface of the placenta is involved 
in the process (PI. XVIII, Figs. 23 and 24). 
In other instances development advances as far as the differentiation of 
the spore mother-cells (PI. XVII, Fig. 22), and then these may begin to 
undergo regressive changes. Even the comparatively few spore mother- 
cells that pass through meiosis afford abundant proof that they also 
1 Juel, H. O., loc. cit. 
J Mr. R. Beer informs us that he has observed this form of nuclear division in pure specimens of 
Oenothera biennis when these flowered late in autumn , but not in individuals blooming at a more 
favourable time of the year. 
