56 EXTENT OF ALBUMEN. [BOOK i. 



mass, as in the albumen oleosum and corneum. In Cinclionads 

 there are thin spots in the horny albumen, as though pores 

 were forming; the same is seen in the horny albumen of 

 some Palms. In the thin- walled cells pores are very evident. 

 With regard to the general arrangement of the cellular tissue, 

 it has a ray-like texture, from its being developed from the 

 walls of the sac towards the embryo, or if that is very small 

 towards the centre of the albumen. With regard to the 

 contents of the cells of albumen, they do not differ much 

 from those of parenchym in general. In Alpinia Cardamomum, 

 formless masses are observed in the cells of the perisperm. 

 Between the cells of Pothos rubricaulis are found larger cells 

 containing some crystallised salt. 



3. On the Albumen of Leguminous Plants. If any one 



should examine the seeds of Cassia, Gleditschia, and Tetra- 



gonolobus, he would find it difficult to account for the fact 



that in recent times albumen had been denied to Leguminous 



plants. Gsertner originally made exceptions to the statement 



that they had no albumen ; it was confined, by Jussieu, to 



the orthoblastic genera. De Candolle called the albumen of 



these plants an Endoplevra tumida, and most botanists have 



followed him. Guillemin and Perrottet, in the Flora of 



Senegal, sometimes call this substance albumen, sometimes 



Endopleura tumida. In order to investigate this subject, and 



arrive at the following conclusion, more than 300 different 



kinds of seeds of Leguminous plants have been examined. 



a. Formation and Presence. The ovule of Tetragonolobus 



purpureus has two integuments covering the nucleus. 



The embryo-sac developes itself in the vicinity of the 



micropyle and grows from thence out towards the chalaza. 



In Brachysema undulatum, the integuments and nucleus 



are not developed till after the embryo-sac and embryo 



appear, and the internal membrane disappears with the 



absorption of the nucleus. In Tetragonolobus the 



nucleus is first absorbed, then the internal membrane, 



the entire length of which disappears at the same time. 



The embryo, in its development, constitutes a transition 



to that irregular form seen in Lupinus. Ordinarily 



that part of the pollen tube which has projected into 



