322 BOTANICAL GAZETTE [OCTOBER 
fig. 2 (7, p. 34), secured when 20 per cent albumose is precipitated in 
a concentrated aqueous solution of sublimate. FiscHer has figured 
both of these bodies of unequal staining capacity, precipitated 
from the same substance and appearing as stages in division. The 
fact that they are secured by precipitation might indicate that in 
Spirogyra we have a similar case. The dumbbell-shaped bodies 
seen frequently in the centrally lying mass may be but stages in 
aggregation and not the beginning stages of division. They are 
probably the bodies described by Bercus (1) and MirzcewrrcH 
(12) as the chromosomes, although in the species studied by these 
writers 12 chromosomes were found. As in S. crassa they are 
variable as to number and shape and in all cases far exceed the 
number of chromosomes heretofore ascribed to S pirogyra, there 
seems to be justification for considering them not chromosomes, but 
rather amorphous masses of chromatin material which will serve as 
centers for the absorption of the less dense surrounding material. 
FIscHER (7) found that nuclein acid granules, as they did not 
become corroded by iron alum, could be stained only a light smoke 
gray with aqueous hematoxylin, but when inclosed in deutero- 
albumose solution their aversion to corrosion by alum salt was 
overcome. This suggests that the clue to the difference in the 
staining capacity of the component parts of the central mass may 
be sought in analogous changes in the composition of the colloids. 
Although both kinds of material, ordinarily in the form of a 
spherical mass, nearly fill the nuclear space, in nuclei fixed with 
Bouin’s mixture this was not found as frequently as the condition 
where the nuclear space is filled with irregularly shaped bodies 
undifferentiated as to stain. 
With the elongation of the nucleus, the nuclear membrane first 
dissolves at the longer axis where the protoplasm condenses. The 
mass of material now gradually condenses, changing from spherical 
to cylindrical, the deeply stained material accumulating more along 
the central axis, Here it may be seen to be composed of oblong 
bodies, when filaments are arranged so as to be seen endwise (fig- 
17), or as filaments somewhat intertwined. In all cases an areolar 
space marks off the entire spherical mass from the spindle. The 
darker stained bodies are also distinguished from the others by 

