ON POLLIN1FEROUS OVULES IN A ROSE. 319 
cardinal importance in vegetable physiology. Indeed, so far as its con- 
formation goes, although the general features of ovule structure are 
tolerably well known, yet the true morphological composition of this 
most important part of the vegetable organization is still a matter of 
controversy. Whether the coats of the ovule are to be looked on as 
foliar organs, as modifications of the marginal lobes of the carpellary 
leaf, or whether they are to be considered as developments from the 
axis, whether the nucleus is to be regarded as a new and distinct 
production of a bud-like character, to which the coats act as protective 
scales, — all these are points, not to mention others, which are still in 
dispute. 
It is therefore no matter for surprise that any deviations from the 
ordinary conformation are looked at with special interest, in the hope 
that they may at least supply a clue towards the unravelling of some 
of the mysteries surrounding the morphological nature of the ovule. 
At present there is no decisive evidence either one way or the other, 
one set of facts and the inferences to be drawn from them beinsr 
counterbalanced by another array of facts, from which opposite conclu- 
sions may be drawn. 
Without going into detail at present, it may here be stated that the 
principal deviations from the ordinary structure of the ovule, which 
have, up to this time, been noticed, are these: — 1. The more or less 
foliaceous condition of the coats of the ovule, — a state of things gene- 
rally coincident with their being flattened like a leaf and not convolute 
or tubular. This flattening in the case of foliaceous or petal-like 
ovules, takes place indifferently, whether the nucleus of the ovule be 
present or not. This change then affects the coats of the ovule, or 
rather the coat, as in such instances only one is developed, and that 
one in a foliaceous or petaloid guise, even in plants where there are 
usually two or more investments to the nucleus, so that the latter 
organ remains almost wholly uncovered. 
2. The next most common teratological change in the ovule consists 
in the development of a leafy shoot in the place of the nucleus. Such 
mi occurrence has been frequently recorded, and I have myself met with 
numerous instances of it, but I have never been able to satisfy myself 
dearly as to whether the leafy shoot in question was really an exagge- 
rated development from the nucleus or whether it was merely a 
new growth, distinct from that bodv, though occupying its ordinary 
• , • 
position. 
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