PHANEROGAMIA : FLOWERS. 



397 



project out more or less. This is often most striking in the external 

 integument, which frequently leaves fully the half of the seed-bud un- 

 covered, as in Zea, Coix, Panicum (fig. 244.). According to Brown, 

 a similar condition occurs in the species of Banksia and some of those 

 of Dryandra ; however, from investigations made upon fresh flowering 

 examples of Banksia insularis and media, I believe that I have a right 

 to assert distinctly the contrary. On the other hand, I have examined 

 an undetermined Banksia from the Berlin botanical gardens, in which 

 it was certainly as Robert Brown states ; but the seed-buds were sus- 

 pended and half-reversed, whilst, with the two species of Banksia just 

 mentioned, the seed-buds were erect and quite reversed. A remarkable 

 form occurs in some Abietinece ; for instance, in Abies (fig. 245. <?.) and 



245 



at A 



Larix, in which the micropyle is extended into two lobes, papillose, and 

 secretes a fluid ; and thus, from its similarity to a stigma, has been the 

 greatest prop of the opinion that the integument is a germen. It is 

 very common for the inner integument to project beyond the outer one, 

 or at least to have its free border uncovered and lying in one plane with 

 the outer integument. Where this occurs, it is common also to find 

 the part of the inner integument forming the endostome swollen, so as 

 to appear somewhat constricted by the rest. In Aracetz, Liliacece 

 (fig. 246.), &c., this is very frequent. Occasionally, but less frequently, 

 the exostome is swollen in a similar way : this occurs, however, in many 

 Euphorbiacece, (fig. 247.), (the so-called caruncula of the seed), as Mirbel 

 has shown. 



247 



244 Panicum miliacewn. Seed-bud in longitudinal section, a, h, Hilum and chalaza ; 

 6, nucleus ; c, embryo-sac ; d, inner, and/; outer integument, tbe last leaving tlie great 

 part of the first uncovered ; y, micropyle. 



245 Abies excdsa. Longitudinal section through the seed-bud, with the upper part of 

 the micropyle (g) uninjured, a, A, Hilum and chalaza ; 6, nucleus ; c, embryo sac ; 

 d, simple integument. 



*" Trillium erectum. Seed-bud in longitudinal section. a, Hilum; 6, nucleus; 

 c, embryo-sac ; d, inner, and /, outer integument ; g, micropyle, formed solely by the 

 inner integument ; h, chalaza. 



* 47 Euphorbia pallida. Seed-bud in longitudinal section, a, Hilum ; 6, nucleus ; 



