1845.] Linnean Society. 265 



from the edges of cup-shaped theca, leaving the grains of pollen free 

 and uncovered. The agency of insects appears, however, to be gene- 

 rally resorted to to ensure fecundation, the lower portion of the spa- 

 tha being found during impregnation to contain many smedl flies, 

 which have perished from inability to escape after the performance 

 of their important duty. 



The ovula, at the earliest period of observation, are described as 

 oblong bodies, having, a little below their points, a slight constric- 

 tion, above which they are papilliform. At a somewhat later period 

 the base of the papilliform nucleus is surrounded by an annulus, 

 which Mr. Griffith describes as a growth from that part of the ovu- 

 lum situated below the constriction, and which is the rudiment of 

 the integument of the ovulum : it soon increases and forms a sort of 

 cup, beyond which the nucleus at first projects considerably. This 

 Mr. Griffith regards as a good example of the correctness of Mr. 

 Brown's opinion as to the comparatively late origin of the integu- 

 ments in the generality of ovula. As the development proceeds the 

 nucleus becomes entirely enclosed in the cup, the mouth of which is 

 gradually narrowed. After impregnation, the period of which is 

 marked by the withering of the spatha, the centre of the nucleus be- 

 comes more transparent, and is evidently excavated. The foramen 

 is still visible, but soon afterwards becomes indistinct. The cavity 

 of the nucleus gradually extends upwards to near the apex of that 

 body and downwards towards the hilum ; its lower portion is occu- 

 pied by cellular tissue, assuming the form of a sac, and quite free from 

 adhesion inferiorly ; while the upper third contains an oblong cel- 

 lular body with a conical apex, which constitutes the rudimentary 

 embrj-o. A little later, the conical, originally rectilinear apex of the 

 embryo has become somewhat oblique, and a depressed areola makes 

 its appearance on one side of the head of the embryo. In the next 

 stage the conical and rather oblique apex of the embryo protrudes 

 through the apex of the nucleus, and its base has become enlarged 

 and roundish. The conical apex and head of the embryo become 

 still further protruded, and from the margin of the depressed areola 

 are produced minute, oblong, obtuse, cellular bodies, which are the 

 rudiments of the outer processes of the plumula. These gradually 

 enlarge, and others are developed within them from the centre or 

 disc of the areola ; and at the same time the conical apex of the 

 embrj'o becomes more and more oblique. At this period the chief 

 bulk and enclosed part of the embryo occupies about the upper 

 two-thirds of the excavation of the nucleus, but does not as yet ex- 

 tend into its lower globular portion ; and the enclosed part is firmly 



