18 PROCEEDINGS OP THE ACADEMY OF [1884. 



becomes the latticed siliceous capsule. The pedicel also becomes 

 more rigid, though always retaining a degree of flexibleness. 

 This manner of reproduction was first described by Cienkowski, 

 the great Russian observer, and discoverer of Glathrulina elegans 

 (see Leidy's Rhizopods of North America). 



In the second mode of reproduction, the rays are not withdrawn, 

 nor does the body divide, but the sarcode becomes finally vacu- 

 olate, presenting knob-like projections. Suddenly a small mass of 

 sarcode, usually one of the knob-like projections, detaches itself, 

 and, passing out of the capsule, shoots out rays and develops, 

 though more slowly, in the manner described above. This con- 

 tinues until the parent body is much redi;ced in size, when the 

 rays again protrude and the animal returns to its normal condition. 



The third mode of reproduction is by the formation and liber- 

 ation of minute germs. In this state, also, the rays are not 

 withdrawn, but the body of the Glathrulina becomes filled with 

 minute green particles, which, even before liberation, exhibit 

 active motion. A number of these are expelled, enclosed in a 

 thin protoplasmic film or globular sac, which bursts shortly, and 

 the liberated germs swim away. The development of these germs, 

 after this point, is yet to be followed. 



The fourth mode is still more remarkable, and is also signifi- 

 cant in bringing to light a new phase in the life-history of the 

 Heliozoa. The Glathrulina in which these phenomena were first 

 observed, withdrew its rays and divided into four parts, as in the 

 ordinary inethod ; but the sarcode, instead of becoming granular 

 and of a rough surface, grew smoother and more transparent. 

 Then followed a period of quiescence ; — in this case of five or six 

 hours duration, although in other instances lasting three daj's 

 and nights ; after which one of the four parts began slowly to 

 emerge from the capsule, a second following a few moments later. 



While passing through the capsule, these masses of sarcode 

 seemed to be of a thicker consistence than the similar bodies, 

 which, in the ordinary method, instantly assume the Actino- 

 phrys form. After both had passed completel}^ through, for 

 nearly a minute they lay quiet, gradually' elongating meanwhile. 

 Then a tremor became visible at one end, and a short prolonga- 

 tion of the sarcode appeared waving to and fro. This elongated 

 at the same time into a flagellum, the vibrations becoming more 

 rapid, until at the same moment both the liberated-monads darted 

 away through the water. Thej^ were followed for about ten 



