ON HIPPOCRATEACE.E. 221 



2. In the former, the stamens are distinctly inserted inside the disk ; 

 in the latter, they are invariably inserted outside the disk. 



3. In the former, the anthers, generally of a peculiar form, are con- 

 stantly extrorse ; in the latter, they are of the usually normal structure, 

 and always introrse. 



4. In the former, the disk is generally elevated, and presents a free 

 wall of separation between the stamens and" more external parts ; in the 

 latter, it is a mere expansion of the torus, intervening between the ovary, 

 and all other floral parts. 



5. In the former, the sepals, petals, stamens, and disk are persistent 

 at the base of the fruit, and are never seen in such position in the latter 

 family. 



6. In the former, the superior ovary is always elevated above the torus, 

 and quite free from it ; in the latter, it is always more or less partially 

 imbedded in the disk, and half agglutinated with it. 



7. The atrophied condition of the axis of the ovary, though not a con- 

 stant feature, is one quite peculiar to the Hippocrateacere ; and on the other 

 hand, in Celastracers we tind no growth at all approaching the several 

 kinds of large drupaceous fruits seen in the Hippocrateacea:. 



8. In the development of the seeds there is a constant distinction. In 

 Hippocrateacece they are invariably without albumen ; in the CelaatracecB, 

 the embryo, without exception, is enveloped in albumen, usually copious. 

 In the former, the cotyledons are often closely conferruminated in a solid 

 mass, a circumstance quite unknown in the latter. 



9. In the Hippocrateacece no trace of an arillus can be seen; in Celas- 

 traceee, though not universal, a distinct arillus in most cases partially sur- 

 rounds one extremity of the seeds. In the former, in one tribe, the seeds 

 exhibit a greater or smaller expansion of the testa, in the shape of a large 

 membranaceous wing, or a narrower alar keel, while in the two others they 

 are invested by an ariUine, an entire fleshy coating, the nature of which 

 Mr. Miers explained many years ago, — a feature seen in some other fami- 

 lies, though too often unnoticed by botanists. 



10. In the Hippocrateacece, the leaves, but more particularly the 

 branches of the inflorescence, the pedicels, sepals, petals, contain nume- 

 rous white elastic threads, which hold the parts together when broken ; 

 and these spiral threads often extend to the pericarps, to the integuments 

 of the seeds, and even occasionally to the fleshy cotyledons. Nothing of 

 this kind has yet been observed in Celastracece. 



Any one of these peculiarities, by itself, would tend little to support 

 any separation of these two families, but the sum of the whole tells power- 

 fully to mark a great distinction in their organization. The only argu- 

 ments that have yet been urged for their near affinity are that both 

 generally consist of arborescent plants, with evergreen leaves, an axillary 

 inflorescence, petals and sepals with imbricated {estivation, a 3-celled 

 ovary, a simple style and stigma ; but these are all characters common to 

 many other families, distantly related, and wholly insufficient by them- 

 selves to establish any near affinity. The more probable inference is t^liat 

 these two families should be separated by a long interval. 



