OLIVE : MONOGRAPH OF THE ACRASIEAE. 471 
one mass of individuals. He mentions, for example, to support tiis 
conclusion, one instance in which ten fruit bodies resulted from the 
transfer of one mass to the nutrient medium. 
During a careful study of the behavior of fructifying colonies 
when transferred to hanging drop cultures, I have seen also that 
several small fructifications may undoubtedly be produced from one 
disintegrated pseudoplasmodium; but I have found no evidence 
whatever of the resumption of a vegetative existence or of an 
increase in the number of individuals. I have placed, for example, 
pseudoplasmodia of various degrees of development in hanging drops 
of nutrient decoction, and have without exception observed that the 
colony at once begins to form a stalk carrying the developing fructi¬ 
fications out of the liquid. In one instance, a single pseudoplasmo¬ 
dium of Dictyostelium was transferred to a hanging drop of distilled 
water, and after a few hours, four fructifications were formed from 
the mass. At another time, a young colony of myxamoebae in a 
water drop was broken up with needles into several small aggrega¬ 
tions, each of which resumed at once its course of development and 
formed an independent fructification. 
It is evident, therefore, that the production of several fructifica¬ 
tions from one mass does not necessarily signify an increase in the 
number of individuals, but the phenomenon is due rather to the 
breaking up of the mass into several fructifying portions in conse¬ 
quence of the interruption of the normal development. 
Even when the pseudoplasmodium is not visibly disturbed, it 
occasionally happens that the usual course of development will be 
interrupted. For example, the mass, even after it has attained a 
considerable size, may separate and the constituent individuals go to 
augment some other colony near by. It is possible that in such 
instances, the separation of the pseudoplasmodium may have been 
due to the heating effects of the Welsbach lamp used for illumina¬ 
tion in the examination of drop cultures. At another time, the 
writer observed in a culture of Guttulinopsis, many small groups of 
myxamoebae, each composed of a dozen or more individuals, arranged 
at varying distances about, and independent of a large central sorus. 
During the night, however, instead of forming, as might be expected, 
isolated groups of resting bodies, all had joined the central mass and 
formed pseudospores. 
Pseudoplasmodia in various stages of development have been fixed 
