PHANEROGAMIA : FLOWEKS. 



425 



alone can lead to the comprehension of the nature of the plant, and 

 therefore of scientific Botany ; and he it was, especially, who made the 

 first step towards bringing light and order into the theory of the albumen, 

 botanists have allowed it to be told them, and follow the old systems as 

 before. In 1825, Robert Brown showed that two things totally different 

 from each other were confounded together under the term albumen, and 

 demonstrated their simultaneous presence in the NymphceacecB. Eighteen 

 years have passed since that, and not a single botanist has contributed 

 anything to the further development of the subject. Before and after 

 they have talked at random about the nature of things, but investigated 

 nothing ; and the treatises given by Mirbel and Brongniart in 1829-30 

 have been passed over without a trace : and we always find that in the 

 most recent works of renowned botanists, Nymphceacece, &c. are de- 

 scribed as Monocotyledons, and the albumen is mentioned without any re- 

 ference to its origin. My friend Vogel (who too early fell a sacrifice to 

 his zeal for science), with myself, endeavoured, in a memoir on the 

 albumen*, to bring light and order into this subject. In the paragraphs 

 I have given the essential portion of our results : many specialities are 

 also unfolded in that essay, in which we have demonstrated, in an 

 extensive treatise on the albumen of the Leguminosce, that this is a 

 true endosperm, and not, as DeCandolle thought, a thickened inner 

 integument. 



The important conditions may be seen by comparing together the seed 

 of Typha (fig. 265.), where endosperm alone is present ; of Saponaria, 

 (fig. 266.), where only perisperm exists ; and of Nymphcea (fig. 267.), 

 where both occur simultaneously. 



265 



267 



(I 



266 



171. The integuments of the seed-bud, in which I here include 

 the nuclear membrane, are also very variable in their ulterior de- 

 velopment. Sometimes, but extremely rarely, they become wholly 



* Act. Acad. L. C. N. C. vol. xix. pt. ii. I here remark, since the usual title notice 

 of the time of sending in has been omitted by the Editor, that this essay was sent in 

 and received for printing by the Editor in 1838. 



265 Typha latifolia. Fruit in longitudinal section. a, Integument of the fruit ; 

 b, integument of the seed ; c, operculum ; d, endosperm ; e, embryo. 



866 Saponaria officinalis. Seed in longitudinal section, a, h, Ililum and chalaza ; 

 </, coat of the seed ; b, perisperm ; f, embryo. 



* 67 Nymphtea alba. Seed in longitudinal section. a, g, Hilum and micropyle ; 

 h, chalaza ; d, seed-coat and its epidermis ; b, perisperm ; <, endosperm ; f, embryo. 



