38 THE AEEANGEMENT OF THE 



we shall see as follows: The nucleus is surrounded by a yellowish shining 

 shell, which either is uniform in its width or looks beaded, as if built up by a 

 number of granules, which are connected with each other by a thinner layer 

 of the same substance of which they themselves are composed. Within the 

 nucleus we again find granules, either uniform in size or some appearing to 

 be considerably larger than others ; these latter bear the name of nucleoli. 

 The granules vary greatly in number, and are either scattered irregularly 

 throughout the nucleus or are arranged in the shape of wreaths, concentrical 

 with the outer shell of the nucleus. Sometimes two or even three of such 

 wreaths are to be observed within the nucleus, a fact to which Th. Eimer first 

 drew attention. In small nuclei we observe sometimes only one central 

 granule (nucleolus), and from this granule there project fine threads, from 

 three to six in number, conical in shape, the bases of the cones arising from 

 the granules, their thin ends tending toward the wall of the nucleus, with 

 which all the cone-like threads are invariably in direct union. Thus a wheel- 

 like figure is constructed, the hub of which is represented by the central 

 granule (nucleolus), the spokes by the conical threads, and the felloes by 

 the shell or outer layer of the nucleus, the latter representing only the 

 optical section of the surrounding layer of the spheroidal body. All the 

 described formations are suspended in a pale, colorless, and structureless 

 substance, between which and the fluid part of the blood outside the 

 corpuscles no distinction can be drawn. When there are several granules 

 present in the nucleus, all are joined together by means of fine, grayish 

 threads, the granules thus representing the points of intersection of a net- 

 work which traverses the whole interior of the nucleus. The granules next 

 to the wall of the nucleus it is immaterial whether regularly or irregularly 

 placed send delicate grayish threads toward the wall of the nucleus, with 

 which they inosculate. The meshes of the net-work within the nucleus, filled 

 with the homogeneous colorless substance, vary in size. I, however, was not 

 able to decide whether, during the motions of the whole corpuscle, there 

 were also changes in the shape of the net-work of the nucleus, which S. 

 Strieker asserts he has noticed in the net-work of the nuclei of the colorless 

 blood-corpuscles of the frog and newt. 



The structure of the nuclei, as just described, is visible on all nuclei, no 

 matter how many may be seen within a protoplasmic body, and also on bodies 

 floating in the fluid specimen which were described before as free nuclei. In 

 none of the latter could I ever discover changes of shape or active locomotion. 

 Not very rarely, however, we meet with small nuclei in the blood-corpuscles, 

 which look almost homogeneous and of a pale, grayish-yellow color, appar- 

 ently devoid of structure. Such nuclei, which we might consider as some- 

 what larger granules, are also suspended in the outside fluid part of the blood, 

 as well as in the protoplasmic bodies. 



Whenever a nucleus is to be seen in a protoplasmic body, outside its shell 

 a light seam can be observed, always traversed by conical, radiating threads, 

 which spring by their broad bases from the shell of the nucleus, and unite by 

 their thin ends with the granules next to the light seam. Such conical off- 

 shoots arise also from compact nuclei, thus giving them the appearance of 

 angular bodies. Throughout the whole protoplasm granules of different sizes 

 are scattered, all of which show the same color and the same power of refract- 

 ing the light as those within the nuclei. These granules are united with each 

 other by slender threads in the same manner as those in the nuclei. Very 



