620 Wolfe . — Cytological Studies on Mentation. 
connexions, escape as carpospores through a terminal break in the mother- 
cell wall, which is left behind as an empty adherent sheath, and within 
which, by further successive proliferations, several more mother-cells of 
carpospores may be produced, from which a corresponding number of 
spores are successively discharged (Text-fig. 51). 
The function of the stalk-cells of the carpogenic branch can be stated 
in brief to be that of furnishing organized material to the rapidly growing 
cystocarp. Whether or not the heavily staining masses appearing in 
these cells (Figs. 21 and 22) represent food material, as is suggested by 
Wille and as further indicated by their disappearance as the cystocarp 
develops, is a matter of some uncertainty. At least a portion of this 
material, in the writer’s opinion, results from the disorganization of the 
chromatophores which disappear during the early development of the 
cystocarp (Figs. 2 1 and 22). 
Mitosis (Centrosome, Spindle, &c.). 
In the mitoses of this plant two heavily staining masses invariably 
appear at the poles of the spindle at metaphase, with the possible exception 
of the antheridial mitoses already mentioned, which, it would seem, are 
certainly to be identified with the structures usually described as centro- 
somes. In Nemalion this body is of relatively large size and always sur- 
rounded by a delicately outlined hyaline area (PI. XLI, Figs. 63, 67, &c.), 
although within this region no fibrous radiations could be satisfactorily 
observed. The occurrence of instances in which it appeared to divide 
(Figs. 63 and 70), together with such conditions as are illustrated in 
Fig. 53, make it probable that the centrosome is always present even 
in the resting condition, and corresponds to the bodies thus designated 
in many plant and animal-cells. While its size alone would make it 
a favourable subject for research, the fact that it has not been shown 
to be accompanied by an aster, or any other very characteristic structure 
which might serve to differentiate it clearly from the granules of food 
and other material which react to stain in much the same manner, has 
led the writer to refrain from attempting at this time to examine it in 
more detail. 
The spindle is organized within the original nuclear cavity, and 
possibly from a residual non-chromatic nucleolar substance which may 
be seen as a lightly staining mass, apparently fibrous in character, 
occupying the central region of the nucleolus after the chromatic substance 
has all passed to the nuclear wall (Figs. 56 and 60). No indication 
whatever of an extra-nuclear origin for the achromatic structure was 
ever observed. The suspending fibrillae already mentioned (Fig. 54 ) 
may of course co-operate with this nucleolar matter. The spindle may be 
