OLIVE : MONOGRAPH OF THE ACRASIEAE. 
461 
uals. Strasburger (’84), Harper (:00) and others further find that 
the nuclei and nuclear division in the fructifications of the same 
group are of the ordinary type. 
' The nuclear phenomena in the related Amoebae are so various 
and the conditions are so little known, that it is difficult to compare 
these organisms structurally with the myxamoebae of the Acrasiehe. 
For example. Amoeba protea has but one nucleus, while Amoeba 
binucleata possesses two. The details of nuclear structure and divi¬ 
sion have been recently described by Dangeard^ (-00) Schaudinn 
(’95), and the latter is of the opinion that in certain species, at any 
rate, the chromatin is in the form of minute granules which are 
arranged about the periphery of the nucleus while the central portion 
is occupied by an ^‘intra-nuclear division center.” So far as I have 
been able to discover, the nuclear conditions present in the myx¬ 
amoebae of the Acrasieae do not closely resemble either those seen 
in the Amoebae or those present in the amoeboid condition of the 
Myxomycetes. 
Primary division of the myxamoebae .— The first type of division 
‘ in the young individuals, which may for convenience be assumed 
to correspond to an indirect division and which I have repeatedly 
observed, was apparently not distinguished by Brefeld, who was of 
the opinion that division of the nucleus probably occurred in the 
short time during which the myxamoebae are rounded, preceding 
the ordinary vegetative multiplication. This short time is evidently 
inadequate for any such complicated changes as those which usually 
accompany karyokinetic division, while the phenomena which will 
now be described occupy a number of hours. 
The young individuals, having made their exit from the spore 
.wall, in germination, retain for a long time the oval spore shape, 
and during the slow swelling which occurs, develop one or more 
contractile vacuoles. Granules then appear in the cytoplasm; some¬ 
times but one rounded refractive body enclosed in a small vacuole, 
but more frequently several small granules, occurring usually near 
the two ends (pi. 6, fig. 49-54). From the subsequent behavior of 
these refractive bodies, I have been inclined to regard them as the 
chromatin material of the cell. They become more and more con¬ 
spicuous and finally appear to be arranged along an irregular thread 
which suggests a spirem (pi. 6, figs. 55, 56). The granules are next 
aggregated so as to form a group possibly comparable to a nuclear 
