1.30 



nucleated protoplasm is threaded thickly with extremely fine 

 non-medullated nerve-fibres coming up from the interior and 

 extending in horizontal directions, but which I have not 

 had the opportunity of studying sufficiently closely. It is 

 manifestly enough the outer of the two densely nucleated 

 strata figured by both Besser^ and Arndt in the infant 

 brain. 



Passing more deeply a broader stratum is gradually reached, 

 in which the nuclei are much sparser and can be distin- 

 guished as of two kinds, those which are free, and those 

 which are situated within minute nerve-corpuscles of a 

 pyramidal form, with the apex pointing to tbe surface; and 

 it may be admitted witli Arndt that many of the free nuclei 

 are somewhat smaller and less easily stained with carmine 

 than those within the nerve-corpuscles; but the difference 

 in these respects is not such that a deductifm can be safely 

 founded on it. This is the fourth layer of Arndt, the super- 

 ficial part of what Lockhart Clarke latterly calls the second 

 layer. 



Passing still inwards the nerve corpuscles are found to 

 enlarge, and a considerable depth of tissue is reached, cha- 

 racterised by pyramidal nerve-corpuscles of greatly increased 

 size, forming, beyond question, the fifth layer of Arndt ; but 

 if it be examined with great care, particularly in a carmine- 

 stained preparation, there will be found, after passing a 

 certain drpth of these corpuscles, a defined band of closely 

 a(T(rre<'ated free nuclei of small size, constitutino- the outer of 

 the " Kornerschichten " of Meinert,^ already alluded to as 

 the nucleated protoplasm of the primary ])ale band. 



This stratum 1 have never failed to find; it is as distinct 

 from the texture above and btlow it as the milky way is 

 from the rest of the heavens ; but as the slide is passed across 

 the field of the microscope, it is easy to understand how it 

 might escape observation not specially directed to it. If 

 difficulty be experienced in finding its position, it may be 

 detected by liolding up the slide on which is the section 

 against the light, noting the sharp line which separates the 

 primary pale band from the subjacent texture, and placing a 

 speck of gum on the cover, so as to touch the deep margin 

 of the line. On examination under the microscope, the band 

 of clerse nuclei will be seen touching the speck with its deep 



' Besser, in Vircliow's ' Archiv,' vol. xxxvi; T;if. vii. 



^ 1 reo;iel that 1 have not. yet. seen Meinert.'s paper, pnblislied in the 

 ' Yierteljahibchnl't liir I's^chialrie/ vol.i; but it is copiously let'errtd to by 

 Arndt. 



