96 JOURNAL OF THE [April, 



coming quiescent, took a globular shape, retaining both flagella 

 to the last. This sphere then grew larger and its wall thinner 

 until, like a bubble, it burst, liberating the germs, which were 

 always present, and very active (Fig. 3). So many of these forms 

 were now found, while the number of the adult forms of Chilo- 

 monas at the same time diminished, that the identity of the two 

 was suspected ; and the suspicion was verified almost immedi- 

 ately by my witnessing the transformation throughout. 



An individual would begin to spin round, gradually losing 

 contour, while the refractive " corpuscles " ranged near the cell- 

 wall left their places and moved actively about, showing, as did 

 also the increased transparency of the cell, incipient liquefac- 

 tion of the endoplasm. An amoeboid character was now assumed 

 until, finally, one or the other of the two phases above noted 

 was entered upon. When the final shape was that of Fig. 4, the 

 freeing of the germs was effected in various ways. Sometimes, 

 as stated, the film became generally disintegrated. In other cases, 

 one large external vesicle was formed, leaving only a very small 

 portion of protoplasm enclosing the germs, and from this 

 the germs energetically freed themselves after the bursting 

 of the vesicle (Fig. 5). In still others, a small vesicle formed 

 about the germs and, moving to the cell-wall, extruded itself, 

 and burst, liberating the germs directly into the water, after 

 which, the remainder of the animalcule disintegrated (Fig. 6). 



In from four to five days each of these germs developed into 

 an adult Chiiomonas, having the characteristic form at an early 

 stage of growth. The " corpuscles," or, correctly, the germs, 

 appeared in these at maturity. 



The habit of breaking up, as recorded by Biitschli, probably 

 coincides with the above phenomena, and, although that author 

 does not describe the liberation of germs, I believe this habit to 

 exist principally for that purpose, as the young, or recently 

 matured, Chiiomonas was not affected by confinement. This, 

 then, seems to be the first time that the true character of the 

 ornamental belt of so-called corpuscles has been indicated. 



The transition to the globular and the amoeboid phases 

 afforded strong corroboration of the opinions of Stein and Kent, 

 as opposed to that of Biitschli, regarding the point of growth of 

 the flagella, — showing them to be inserted close together. 



