Pammel — Anatomical Characters of Seeds of Leguminosae. 95 



Cuticle. — The cuticle makes its appearance quite early in 

 the development of the ovule. In the mature seed it is repre- 

 sented by a delicate line, as a rule of nearly equal thickness. 

 On the addition of chlor-iodide of zinc or iodine and sul- 

 phuric acid, it is colored yellowish-brown. It is dissolved in 

 Schulze's mixture. 



The cuticle has the well-known property of not allowing 

 water to pass through, or only with difficulty. The waxy or 

 fatty nature of the cuticle is repellent to water.* Its thick- 

 ness is correspondingly increased in the seeds of Mucuna, 

 Gymnocladus, and Glediischia, where germination proceeds 

 rather slowly. The remainder of the cell-wall in leguminous 

 seeds is not homogeneous but there is a more or less differ- 

 entiated part which I have designated as the cuticularized 

 portion, though not necessarily chemically the same substance. 

 Mattirolo and Buscalioni (170. 174) designate the cuticle as 

 ** strato esterno della membrana di rivestimento " or outer 

 covering membrane, and the cuticularized layer as the '* strato 

 interno della membrana di rivestimento'' because the struc- 

 tures do not correspond to those of epidermal coverings. 



Schips (226), who has investigated the question, concludes 

 that the outer layer is the cuticle, and that the layers below 

 are frequently differentiated into two additional parts one of 

 which is more or less mucilaginous. 



The substance of the conical projections colors blue with 

 sulphuric acid and iodine and rapidly dissolves ; a less soluble 

 part also colors blue with sulphuric acid and iodine. Schips 

 compares these with the intracellular mucilaginous thickenings 

 in the cell-walls of some orchids, as described by Noack 

 (414) and Magnin (399). The cuticularized layer is con- 

 spicuous in many seeds of the order, especially in Gymno- 

 claduSy Gleditschia, Cassia, and Parkinsonia. True, it does 

 not always reach the development found in the epidermal leaf- 

 cells of Agave and Aloe, well-known representatives of dry 

 climates, yet the cuticularized layer is well marked. From 

 the interior of this layer occur tooth-like projections that 



♦ Fr^my (337) applies the term cutose to the insoluble material of the 

 cuticle, which is derived from fatty and waxy deposits In the cellulose 

 membrane. 



