466 Transactions of the Society. 



give the appearance under a moderate magnifying power of distinct 

 granules. Hence the descriptive term " granular " was constantly 

 applied to cell-nuclei before the meaning of this appearance was 

 understood. 



Occasionally the nodal thickenings of the spongework are very 

 large, and the connecting strands are relatively fine, and in rare 

 cases it is not possible to detect these strands at all, in which case 

 the nucleus appears to contain clumps of chromatin suspended in 

 its hyaloplasm. 



E. B. Wilson, The Cell in Development and Inheritance, 



1902, p. 22. 



The nucleus is usually bounded by a definite membrane, and 

 often appears to be a perfectly distinct vesicular body suspended 

 in the cytoplasm — a conclusion sustained by the fact that it may 

 move actively through the latter, as often occurs in both vegetable 

 and animal cells. 



Also on p. 31, line 8 : — In the first phase, falsely characterized 

 as the " resting state," the nucleus usually appears as a rounded 

 sac-]ike body surrounded by a distinct membrane, and containing 

 a conspicuous irregular network, which is in some cases plainly 

 visible in the living cell. 



And p. 32 : — In the ordinary forms of nuclei in their resting 

 state the following structural elements may, as a rule, be distin- 

 guished : — 



(ft) The Nuclear Memhrane, a well-defined delicate wall which 

 gives the nucleus a sharp contour and differentiates it clearly 

 from the surrounding cytoplasm. This wall sometimes stains but 

 very slightly, and can scarcely be differentiated from the outlying 

 cytoplasm. In other, and perhaps more frequent cases, it 

 approaches in staining capacity the chromatin. 



(h) The Nuclear Reticulum. — This, the most essential part of the- 

 nucleus, forms an irregular branching network or reticulum, which 

 consists of two very different constituents. The first of these, 

 forming the general protoplasmic basis of the nucleus, is a sub- 

 stance known as linin, invisible until after treatment by reagents, 

 which in sections shows a finely granular structure and stains like 

 the cytoplasmic substance, to which it is nearly related chemically. 

 The second constituent, a deeply staining substance known as 

 " chromatin," is the nuclear substance ]jar excellence, for in many 

 cases it appears to be the only element of the nucleus that is 

 directly handed on by division from cell to cell, and it seems to 

 have the power to produce all the other elements. The chromatin 

 often appears in the form of scattered granules and masses of diffe- 

 ring size and form, which are embedded in and supported by the 



