OLIVE : MONOGRAPH OE THE ACEASIEAE. 
495 
the latter forms a perfect connecting link between the Amoebae, 
with which it has perhaps closer relationships, and the Acrasieae. 
In tracing the relationship of the allied Myxomycetes, de Bary 
goes a step below the Amoebae to the Flagellatae. As he has 
pointed out, the occurrence of such a significant stage as the flagel¬ 
late swarm cell condition so early in the developmental history of 
the Myxomycetes, renders highly probable the near genetic relation¬ 
ship of this group with the Flagellatae, with which, however, the 
Acrasieae show no close and direct connection. Zopf has further 
shown that the Myxomycetes are probably closely related to certain 
forms of the Monadineae. 
It may be suggested in this connection, that we have in the ten¬ 
dency of the members of the Acrasieae to form the so called fructify¬ 
ing colonies of individuals in response to chemotactic influences, 
probably a plant character rather than an animal one. While it is true 
that many Protozoa respond to certain stimuli and some undoubted 
members of this group may even form colonies of vegetating cells- 
resulting probably in most cases from an incomplete separation of 
daughter individuals, no known protozoan, so far as I am aware, 
forms aggregations for the evident purpose of forming resting 
masses of spores or cysts, as do Diplophrys stercorea, and probably 
other members of the Labyrinthuleae, the Acrasieae, the Myxomy¬ 
cetes, and the Myxohacteriaceae. 
Opinions have varied much concerning the possible relationships 
that the Mycetozoa may sustain to higher forms. De Bary has 
influenced opinion in this respect more perhaps than any other 
investigator because of his belief that these organisms are the termi¬ 
nal membei’S of a series of forms, and that they do not connect with 
any higher group, while others have sought to show genetic con¬ 
nection with the Fungi in various ways. It is of historical interest 
only that Fries (’29) placed the slime-moulds among the Gaster- 
omycetes on the strength of a mere superficial resemblance between 
the mature sporangia in the two groups; while Brefeld (’69), at first 
misled by erroneous interpretations, held the opinion that Dictyo- 
stelium might connect the two groups through Mucor. Cornu’s 
belief that the Mycetozoa might be connected with the Fungi 
through those Chytridineae which produce amoeboid cells, was per¬ 
haps founded on a more substantial resemblance. For example, the 
Myxochytridineae, in their 23ossession of flagellate or amoeboid 
