1893.] MICROSCOPICAL JOURNAL. 313 



these accumulations of chromatin appear to have no connection 

 with the nuclear membrane, but each nucleus seems to have a 

 well defined nucleolus. Under a power of 1200 diameters, 

 however, the connection between the strands of the reticulum 

 and this central body stand out clearly. This aggregation of 

 chromatin may be condensed and in some instances may be 

 described as spheroidal, in other more numerous instances it is 

 elongated, and with its radiating strands of the reticulum, looks 

 very much like a bone lacuna with its canaliculi. Usually but 

 one such body is found in a nucleus, but occasionally there are 

 two side by side, or both near the nuclear membrane, and it is 

 not rare to find four or five. From the behavior of these local 

 aggregations and the strands of the reticulum to hsematoxylin, 

 it is not possible to determine a difference. Both have about 

 the same tint, and any slight difference of shade maybe attribut- 

 ed to the quantity of colorable matter present in the aggregations. 



In situations where it is to be supposed that cell multiplica- 

 tion is proceeding rapidly, as in the Wolffian bodies and in the 

 inner lining of ths cerebral vesicles and central canal of the de- 

 veloping cord, many nuclei are found whose nuclear membranes 

 are indistinct, in many cases invisible. These nuclei, however 

 are quite conspicuous, owing to the fact that chromatin is no 

 longer disposed in the shadowy strands, but is in heavy solid 

 skeins, taking a much deeper stain than any part of the resting 

 nuclei. Moreover these deepl}^ staining bodies of chromatin in 

 these nuclei assume the position of the nuclear membrane, 

 thus forming a basket with irregular meshes. Thus far I have, 

 not been able to determine whether in these nuclei it is a single 

 skein, or a number of segments, in the formation of this basket; 

 but in certain nuclei where the basket was not very regular, de- 

 tached segments were certainly determined. In some nuclei in 

 which karyokinesis was well established the loops of chromatin, 

 or chromosomes, were seen scattered through the nucleus, as if 

 the basket had been broken into fragments and crushed in. 

 No traces of the nuclear or achromatic spindle were seen before 

 the monaster stage. 



The monaster stage was seen in many nuclei, but the best 

 view was always obtained when the acromrtic spindle was ly- 

 ing at right angles to the line of vision. When the aster was 

 seen from the pole the chromosomes were in such a tangle that 



