OLIVE : MONOGRAPH OE THE ACRASIEAE. 
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his classic monograph, admitted Dictyostelium into the group of 
Mycetozoa, and it was not until 1880 that van Tieghem discovered 
the fact that the so called plasmodiurn of this organism was readily 
separable into its constituent individuals when placed in a drop of 
water. 
Cienkowsky in 1873 described as Guttulina rosea^ a form found 
in Poland on decaying wood, which, in his opinion, was evidently 
similar in some respects to Dictyostelium of Brefeld. The paper 
concerning this new organism was read before the society of 
Russian naturalists at Kazan in 1873 and was unfortunately printed 
only in abstract in the report of that meeting. The review in Just’s 
Jahresbericht by Batalin (’73) , to which all later writers on this group 
have evidently referred, is an accurate translation of this original 
meagre description, with the exception of one minor omission. 
Several species of Guttulina and of Dictyostelium were next 
described by van Tieghem in 1880 ; he also gave the name Acrasis 
to a new organism which he had found on decomposing beer yeast. 
In this same paper van Tieghem proposed for the group of organ¬ 
isms characterized by the possession of myxamoebae and aggregation 
plasmodia, the term Acrasieae ; and removing Dictyostelium from 
the Myxomycetes, in which Brefeld had placed it, he grouped it with 
Acrasis and Guttulina. De Bary (’87) accepted this name and 
characterization and incorporated the Acrasieae as a coordinate order 
with the Myxomycetes in the group of the Mycetozoa. 
Yan Tieghem later (’84) discovered on decaying beans another 
peculiar and complicated form, which he called Coenonia. Unfor¬ 
tunately, we can obtain only an inadequate conception of the appear¬ 
ance of this remarkable organism, since no figures accompany any 
of van Tieghem’s descriptions of the Acrasieae. 
About this same time, Fayod (’83) studied a form to which de 
Bary had called his attention, and described it as Guttulina protea. 
Zopf (’85) later changed this name to Copromyxa protea for the 
reason that it seemed to differ from Guttulina in the fact that the 
masses of spores in Fayod’s species were not stalked, whereas in 
Guttulina rosea., according to Cienkowsky’s description, there is a 
differentiation into head and foot portions. In the same paper, 
Zopf further suggested the name Sorophoreae as a convenient term 
to apply to this group of organisms, thus disregarding van Tieghem’s 
earlier term Acrasieae. In a still later classification (’92), however. 
