wn Plant Cytology. 187 
continuous with enclosed nuclear chromatin. The existence 
of such a network has since been demonstrated in a variety 
of species, and in many instances the threads of it link 
together the plastids where such occur. From its bright 
refractive appearance, its evident continuity with the nuclear 
membrane, and its behavior to fixatives, to corroding agents 
and to chromatin stains, I would regard it as an extremly fine 
network, built up of linin and chromatin constituents, con- 
tinuous with similar constituents of the nucleus. 
But with Gardiner’s work on intercellular protoplasmic con- 
tinuity before us, an important though possibly difficult line of 
inquiry will be to ascertain whether the continuity be one of 
the general vegetative protoplasm only, or whether there does 
not exist an intercellular network of linin-chromatin fibres. 
In dividing cells of banana root, bean root, polygonum stem, 
etc., we can at times see in adjacent cells that are dividing, 
strands of a denser substance than the protoplasm, which 
appear to be continuous as longitudinal strize from spindle 
pole to spindle pole. May we not therefore have an intercel- 
lular linin-chromatin network which may link together not 
merely the protoplasmic, but the hereditary substance ?. 
Townsend’s researches on the apparent intimate relation 
between nucleus and cell wall suggest such a condition, while 
the wave-like rhythm of division-activity which traverses 
most filaments of Sprogyra during division, suggest similar 
relations. A careful study of the latter plant has given as yet 
only negative results. 
Before considering the nucleus it may be pertinent to 
inquire as to the value to be placed on differential stains, and 
specially the erythrophil and cyanophil reactions. Since the 
studies by Schwartz and Rosen, so many conflicting views 
have been advanced that Miss Huie’s observations on Drosera 
were specially welcome. Wager’s observations on hymeno- 
mycetous cells prepare us to believe that the relative stain- 
