ISSN:
0362-2525
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The results of the study of certain factors which affect encystment in Didinium nasutum indicate the following: Absence of food constitutes an adverse environmental condition which induces encystment in approximately 50 per cent of the didinia subjected to it, though the presence of a certain amount of food in the cell body is requisite for encystment. The prevention of encystment for 750 generations does not affect the percentage of didinia which encyst in the absence of food, and hence Didinium does not become progressively more disposed to encystment as generations pass. Conjugation does not affect the percentage of didinia which encyst in the absence of food. Metabolic by-products of Paramecium inhibit encystment to a striking degree when didinia are deprived of food in the presence of these products. Metabolic waste of Didinium markedly facilitates its encystment in the absence of food. Hay-infusion culture fluids of different ages have singularly diverse effects on the encystment of didinia in the absence of food; recently prepared infusions inhibit encystment; infusions four to six days old induce encystment in 90 to 100 per cent of the specimens, and infusions seven to fourteen days old, in approximately half of the specimens.
Additional Material:
8 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jmor.1050430208