194 O. P. Bellinger. 



rations of cilia show in the Amoeba a definite framework of tissue. 

 This framework is a finely meshed structure, essentially the same for 

 the "endosarc" and "ectosarc." It is so woven as to form trabeculae 

 with large iuter-trabecular spaces in the interior, and, without essen- 

 tial differentiation, forms the outer (PI. II, Figs. 5 and 6) mem- 

 brane, the wall of the contractile vacuole, the walls of all food 

 vacuoles, and the nuclear membrane. This structure is constant in 

 all these relations and cannot be considered an artifact. 



In a recent paper, ^'Locomotion of Amoeba and Allied Forms," the 

 author has shown that the movements of Amoebae in no way corre- 

 spond to the movements of complex fluids. On the contrary, it is 

 pointed out that Flertwig's contention, that "Das Protoplasma ist 

 kein Gemengsel zweier nicht mischbarer Fllissigkeiten, wie Wasser 

 und Oel, sondern besteht aus einer Verbindung fester, organischer 

 Substanzteilchen mit reichlichem Wasser," holds at every point. In 

 this paper it is suggested that a reticulum of contractile tissue would 

 explain all the facts of amoeboid movement. Since an application of 

 the methods best adapted to preserve cilia, which we know to be con- 

 tractile tissue, demonstrates a reticulum in Amoebae, and since the 

 presence of a contractile reticulum is the simplest explanation of all 

 the facts of amoeboid movement, I think we are justified in assuming 

 that the reticulum demonstrated is contractile. 



In a paper, "Functions and Structures in Amoeba Proteus," Hodge 

 and Bellinger, which is soon to appear from this laboratory, a full 

 report of the work on Amoeba is given, hence this brief reference to 

 the part that bears upon my subject : 



Actinosphaerium. 

 The literature on the structure of the Ileliozoa is extremely limited. 

 Biitschli (1892) speaks briefly of the protoplasm of Actinosphaerium 

 and Actinophyrs. According to him, their protoplasm shows a finely- 

 meshed structure in the ectoplasm, endoplasm and the pseudopods. 

 This structure is not altered in killing with Flemming's fluid, from 

 which he concludes that it is normal. In speaking of the ectoplasm, 

 he says : "After treatment with the osmic mixture already mentioned 

 the meshed structure is everywhere easily recognizable in the ecto- 



