454 
HARVEY E. STORK 
well-defined astral rays, and in Carnoy and Zenker preparations no sugges- 
tion of centrosomes appears. At first sight, under low magnification, one 
can easily be deceived into thinking that the filiform structures one sees 
lead from the nuclei to the sterigmata, since so many of them are found in 
that region of the basidium. Higher magnifications easily clear up any 
such error. It might, however, be a timely warning to say that students 
working with species in which the basidia are small must be on guard against 
interpreting such structures as are here described as kinoplasmic fibrils 
connected with the daughter nuclei. 
It is a significant fact that Juel (13), who used chrom-platinum-acetic 
and zinc chloride-acetic-alcohol fixatives in the study of the basidia of 
nineteen species of the genera Clavaria, Craterellus, and Cantharellus, 
figures in practically all cases a cytoplasm free from granules, fibrils, or 
similar structures. Of Craterellus pistillaris he says, however (p. 20) : 
"Man sieht oft im Basidienplasma diclitere Plasmastrange, die von jedem 
Kern gegen die Basidienspitze hinziehen. Fadige Differenzierungen konnte 
ich in diesen Strangen nicht entdecken." 
The writer believes that the granular and rod-like structures bear a 
relation to the reticular apparatus of Golgi. This characteristic structure, 
first reported in nerve cells, has since been reported by Golgi as well as 
other investigators to be present in a variety of different cells. Bensley 
(i) describes a similar structure in plant cells, and contends that with ono 
type of fixation the vacuolar spaces are shown as separate isolated vacuoles 
while with a special Golgi technique they appear as a closed net. From the 
preparations of the writer, it is of course impossible to say in what condition 
the substance of the cytoplasmic structures in question exists in the living 
cells of Aleurodiscus. All fixation tends to produce in greater or lesser degree 
artificial conditions in the cell and it is necessary to, interpret these artifacts 
in order to get at the nature of the substances in question in the living state. 
From the varying forms that it assumes with different types of fixation and 
from the fact that with certain fixations it disappears altogether, it seems 
reasonable for us to conclude that in the living protoplasm the substance 
exists in the form of a fluid with various substances in solution which have 
a nourishing function and among which are lipoids in colloidal solution. 
Where active growth takes place, as in rapidly enlarging basidia or growing 
sterigmata, the building of new protoplasm makes great demand on these 
substances and they are therefore present in abundance. They are attracted 
to points where active growth is taking place, and such attraction may be 
so strong as to set up definite lines of flowage which, when subjected to a 
fixative, coagulate in the form of the characteristic rods we have described. 
Such a manner of thinking of these structures explains their lying length- 
wise of the hyphae and their direction towards points of growth. It fails, 
however, to explain why they should exist in degenerating basidia under 
the parasitic Tremella (see figs. 16 and 26). 
