IN OSCILLARIA AND TOLYPOTHRIX. 191 
guished botanist, is this: Is it not possible that the supposed 
nuclei are really products of coagulation due tu the reagents 
employed? It might be supposed that the more granular por- 
tion of the cell-contents may become separated from the rest 
and accumulate in a central mass. 
The answer to this objection is, I think, threefold :— 
1. The granular protoplasm can still be clearly seen surround- 
ing the “ nucleus.” 
2. The existence of division-stages in the central body, accom- 
panying the division of the cell as a whole, points clearly to a truly 
nuclear nature. 
3. In Tolypothrix the same bodies which present the characters 
described can be seen in the living state before any artificial treat- 
ment has been applied. 
To this it may be added that the observations just described 
must be taken in connexion with the chemical tests applied by 
Zacharias, which go so far to establish the character of the bodies 
in question as nuclei, agreeing in their reactions with the un- 
doubted nuclei of the higher plants. 
In conclusion, a few words may be said on the general bearing 
of the facts observed. 
In spite of the scattered observations cited at the beginning of 
this paper, it has been the received doctrine up to the present 
time that the Schizophyta contain no nuclei; though it has been 
held that isolated granules of the chemical nature of nuclein 
may occur in their cells. It will only be necessary to quote two 
authorities. Strasburger, in his classical work ‘ Das botanische 
Practicum’ (1884), p. 867*, states that the Schizophyce® and the 
Schizomycetes agree in being destitute of nuclei and of definite 
chromatophores. Goebel (‘ Outlines of Classification, Engl. ed., 
p. 20, 1887), asserts that “ no cell-nucleus is found either in the 
Cyanophyces or in the Schizomycete:.” If the present obser- 
vations, in conjunction with those of Zacharias and others, be 
established, and extended to other members of the group, these 
statements must fall to the ground. The bearing of this is two- 
fold. 
1. The conclusion is important with reference to the general 
theory of the cell. In all plants with nuclei we have good grounds 
* Also in the 2nd ed., 1887. 
