Vol. LI I February, 1927 No. 2 



BIOLOGICAL BULLETIN 



THE ZOOCHLORELL^ OF FRONTONIA LEUCAS. 



C. L. HOOD, 

 UNIVERSITY OF VIRGINIA. 



INTRODUCTION. 



It is common knowledge that many organisms of the animal 

 kingdom harbor within their bodies various forms of algae. 

 Dangeard ('02) writes at length on the probable relation of 

 the zoochlorellae, in Paramecium bursaria, to their host. The 

 experiments of Lipska ('10) on a culture of Paramecium caudatum 

 which contained green algae are also worthy of note. Geza Entz 

 ('81-2) presents evidence which he thinks is indicative of a 

 symbiotic relation between Stentor polymorphus and green algae. 

 Bary ('79) was the first investigator to allude to the relation 

 between the zoochlorellae and their host as a symbiotic one. 

 But Dangeard ('02) says that the relation is incompletely 

 proven, and Bouvier adds that we have not a definite example 

 demonstrating the usefulness of the algae to their host. 



The work of this paper was conducted in an effort to add 

 further knowledge on the relation of endoplasmic algae to their 

 host. The host used in these experiments has been identified as 

 Frontonia leucas Ehrenberg. 



I wish to express my gratitude to Dr. B. D. Reynolds, under 

 whose direction this work was done, for reading the manuscript 

 and making a number of important suggestions. I am also 

 indebted to Dr. W. A. Kepner and Mr. J. B. Looper for helpful 

 advice and criticisms. 



DISAPPEARANCE OF ZOOCHLORELLJE FROM HOST. 



In Frontonia taken from a collection made near the University 

 of Virginia, from a very small stagnant pool, on June 23, 1925, 

 6 79 



