I 
OLIVE : MONOGRAPH OE THE ACRASIEAE. 483 
somewhat with the culture medium, but in the main their measure¬ 
ments are fairly constant for the same species. Another character 
which is constant in the verticellate fructification of Polysphondy- 
lium, is that the sorus at the summit of the main axis is normally 
about twice the diameter of those of the lower whorls, while its dis¬ 
tance above the whorl immediately below is usually two or three 
times the distance between any two contiguous verticels. 
The time required for the complete cycle of the development of 
these organisms varies from two to several days, and a week or 
even more may elapse before fructification occurs, which may then 
continue for a week or more longer. The fructifying portion of 
the life cycle of a single individual occupies but a small part of this 
time, since, after the preliminary aggregation, the formation of the 
stalk takes place so rapidly that the complete fructification may be 
formed in a day or, in some instances, even in a few hours. 
Characters and ger))iination of the pseudospores and spores .— 
The resting bodies in the fructifications of the Acrasieae, as indicated 
above, are readily divisible into two groups: pseudospores., in which 
there is no cell wall secreted about the restino; mvxamoebae, and 
spores, in which a distinct cell wall of cellulose or similar substance 
is formed around the protoplasm of each individual. Pseudospores 
are not true spores according to the usual acceptance of the term, 
but instead they are merely slightly contracted and encysted indi¬ 
viduals. While they may have a more or less evident marginal 
protoplasmic membrane, the wall is never, in my experience, satis¬ 
factorily demonstrable with plasmolyzing agents, nor is it ruptured 
during; g;ermination and left behind as a delicate sac as in all the 
sporiferous genei’a of these organisms. 
Pseudospores are peculiar to Guttulinoj^sis and Sappinia, while 
the other five genera embraced in the group possess true spores in 
their fructifications. When the pseudospores of Guttulinopsis are 
sown on a nutrient substratum, they soon lose their refractAe 
appearance and the granular protoplasmic contents become visible. 
Each swells somewhat, one or more pulsating vacuoles make their 
appearance, and finally, after some time, the individual gradually 
assumes an active vegetative state and crawls away as a myx- 
amoeba (pi. 5, figs. 3, 4, 10-15). 
In my experience, a nutrient medium is necessary to induce the 
germination of both sj^ores and pseudospores. The spores of Guttu- 
