BOT.-VOL. II.] HUS-CASSIA TOMENTOSA L. 333 



Description. 



The nuclei of the pollen-mother-cells oi -Cassia tomentosa, 

 in the stage indicated in figure i, show a nucleolus, which is 

 sometimes vacuolate, and a broken up chromatin thread. 

 The former stains red, the latter blue or red. The cyto- 

 plasm is composed of two parts, one apparently fibrous,^ 

 the other granular. The first is composed of thinner or 

 thicker fibers running in every direction, but more especially 

 from the nuclear wall to the cell-wall, so that the meshes 

 which they form are elongated in a radial direction (fig. i). 

 The meshes are smallest in the neighborhood of the nucleus, 

 and gradually increase in size toward the periphery. 



The other component of the cytoplasm appears in the 

 form of larger or smaller granules situated between and 

 upon the fibers, and showing a tendency to accumulate in 

 larger or smaller masses, especially at the intersection of 

 the fibers. The fibers can be stained blue with gentian 

 violet, while the granules stain brown-violet. The whole 

 presents a very uniform appearance, except here and there 

 where a thicker fiber or a denser accumulation of granules 

 shows more prominently. 



Scattered irregularly through the cell may be seen small 

 dark round bodies, apparently oil globules, to judge by their 

 appearance in fresh material. It may be of interest to note 

 that while these bodies were very numerous in some cases, 

 especially in the early stages, in others they were rare and 

 were then found but seldom in the later stages. 



Gradually the cytoplasm around the nucleus begins to 

 change in appearance : the change takes place in a single 

 layer of meshes immediately adjacent to the nuclear wall; 

 these meshes become smaller, due perhaps to the interpola- 

 tion -of new fibers, and to the appearance immediately 

 around the nucleus of granular matter, situated upon and 

 between the fibers, often completely obscuring them. The 

 meshes now become elongated parallel to the nuclear wall; 



1 The description of the structure of the cytoplasm refers to microscopical appearance 

 only, without indicating whether it is a reticulum or a foam-structure. 



