I 



47 



caulis are found larger cells containing some crystallized 

 salt. 



3. On the Albumen of Leguminosce. — If any one should 

 examine the seeds of Cassia, Gleditschia, and Tetrago- 

 nolobus, he would find it difficult to account for the fact that 

 in recent times albumen had been denied to Leguminosae. 

 Gaertner originally made exceptions to the statement that 

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

 orthoblastic genera. DeCandolle called the albumen of these 

 plants an Endopleura tumida, and most botanists have fol- 

 lowed him. Guillemin and Perrottet, in the ''Flora of 

 Senegal," sometimes call this substance albumen, sometimes 

 Endopleura tumida. Braun, in a review of that work, 

 pointed out the fact of the existence of albumen in this family, 

 but did not carry out his views. In order to investigate this 

 subject, and arrive at the following conclusion, more than 

 300 different kinds of seeds of Leguminosae have been 



examined. 



3 a. Formation and Presence.— The ovule of Tetragono- 

 lobus purpureus has two integuments covering the nucleus. 

 The embryo-sac developes in the vicinity of the micropyle 

 and grows from thence out towards the chalaza. In Brachy- 

 sema 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, consti- 

 tutes a transition to that irregular form seen in Lupmus. 

 Ordinarily that part of the pollen tube which has projected 

 into the embryo-sac becomes changed into a part ot the 

 mbrvo ; but in Lupinus only a part of the tube becomes 



organized with the embryo, the remaining portion forming 

 little cord-like body, called by Mirbel the suspensor. As the 

 embryo-sac extends, it forms cells out of the mucous and 

 saccharine solution in its inside, the cells being developed 

 around the cytoblasts in the manner described by bcnleiden. 

 At the same time this cellular tissue is forming the embryo 

 increases in size, and either absorbs this or presses it more or 

 le<s together; in the latter case it is the seat of the deposit 

 of albumen. This is often the case, and in most instances 

 the nucleus is entirely absorbed. Hence the albumen of 



