58 ALBUMEN OF LEGUMINOUS PLANTS. [BOOK i. 



even in the genera, to which it was supposed to apply. 

 Nor is a large quantity of albumen accompanied with 

 simple leaves of the plumule, as was supposed by Braun. 

 In opposition to the oft-repeated assertion of Adanson, 

 Jussieu, and De Candolle, it is found that all the principal 

 divisions of Leguminous plants, except Swartziese and 

 Geoffrese, of which only one seed was examined, possess 

 albumen. 



b. Structure. If a layer of albumen is cut, it is transparent, 

 almost of a horny consistence, becomes gelatinous in 

 water, is almost insipid to the taste, and consists of 

 vegetable jelly (P. pflanzengallerte of Schleiden) or 

 mucus (P. pflanzenschleim of Berzelius). In most cases 

 the colour is whitish, in some beautifully white, as 

 Cytisus, Kennedya, &c. When it is transparent, so 

 long as the testa remains on, it has a variety of colours. 

 In Bauhinia microphylla, the albumen was of a wood- 

 yellow colour. Where the albumen is tolerably well 

 developed, three layers are observed; first, that next 

 the testa with regular cells, well defined walls, and 

 ordinarily granular mucous contents : the cells are 

 arranged in only one row. This layer is well seen in 

 Astragalus hamosus, Sesbania cannabina, &c. In the 

 second layer there is a number of variously formed cells, 

 constituting the great bulk of the albumen ; these are 

 succeeded by a third row placed next the cotyledons, 

 which are small and without granular contents. In the 

 middle layer the cells have either very sharply defined 

 walls, or they are lost in jelly. The former are most 

 common in Papilionaceae, the latter in Csesalpineae. 

 When the walls of the cell are evident, jelly is found 

 in the inside of the cell, often obstructing the entrance 

 of the light, as in Sesbania cannabina, &c., it is entirely 

 obstructed in Securigera coronilla. Frequently the 

 cavity of the cell presents a star shape, from the form- 

 ation of pores in the jelly, or gelatine, as in Cytisus, 

 Laburnum, &c. Intercellular spaces are seen in Amor- 

 pha fruticosa, See., which are also filled with jelly. These 

 form a transition to those in which the cells are entirely 



