74 loi'RNAI. Ol- CoMl'A K All \'K NkI'HOI.OG^. 



are identical. Both the white and the red corpuscles of the 

 blood have special localities in which they are elaborated. 

 Why may not Deiter's corpuscles have a special locality in 

 which they are developed and trom which they migrate in all 

 directions? The numerous Deiter's corpuscles that are found 

 in the vicinity lead one to suppose that the caudate portion 

 of the striatum is such a locality. 



Prof. His has shown that the original nerve cells develop 

 from small corpuscles, the neuroblasts.(') Why may not all 

 nerve cells be formed in the same way? Why may not tnese 

 so-called germinative corpuscles of the striatum be the neuro- 

 blasts of future nerve cells? 



Whatever the function of these corpuscles, the evidence 

 that they are produced in the caudate portion of the striatum 

 is most conclusive. Anywhere within this part of the brain 

 the one- fourth inch objective will reveal the whole process. 

 Within its field of view may be observed cells of all sizes 

 and ages. There is the normal cell with one nucleus and 

 one nucleolus. Of the same size as this cell, but a little 

 older, is the cell with one nucleus and two nucleoli. Then 

 come cells of two, three and more nuclei. The size of the 

 cells seems to endeavor to keep pace with the number of 

 nuclei. This is not fully accomplished, but cells that con- 

 tain eight or nine nuclei are two or three times the size of 

 the original cells. Such a cell may be regarded an aged one. 

 Its period of activity has passed. It becomes decrepit. 

 Little by little it fades away, until eight or nine clustered 

 nuclei are the only remains of its former greatness. These 

 nuclei are not inactive. Soon they migrate to other parts of 

 the brain, bearing within their walls the substance of the 

 mother cell (Plate VIII, Fig. lo). 



Internal Capsule. — Between the striated and caudate por- 

 tions of the striatum there is a sheet of fibres that may be 

 considered as the homologue of the internal capsule. 



I Arcliiv fur Physiologic uiid Analomie, 1890. 



