No. 3.] STUDY OF STENOSTOMA LEUCOPS O. SCHM. 267 



with the network. These cells vary much in size, ranging from 

 2 yu. to 4 /i in diameter. They are finely granular and take a dark 

 stain with haematoxylin. They have large round or oval nuclei 

 which range from i /a to 2.5 /x in diameter. These nuclei are 

 stained much darker than the cells. In the nuclei of some of the 

 cells may be seen eccentrically situated very dark nucleoli .5//, 

 in diameter. 



Graff (IZ2, p. 6%) divides the parenchyme of Rhabdocoels into 

 — I, "sagittal Muskel-fasern " ; II, " Bindegewebsbalken " ; III, 

 "Bindegewebszellen." He describes the "sagittal Muskel- 

 fasern " as long, strong fibres of uniform width and of a smooth 

 shining appearance, which are present in only a few Rhabdocoels 

 {Mesostoma, Vortex, and Proboscida). They run through the 

 parenchyme from one part of the integument to another. In 

 Mesostoma some fibres run from the alimentary canal to the 

 integument. The " Bindegewebsbalken " are the meshes of a 

 finely granular network which run in an infinite number of 

 planes. Sometimes these meshes broaden out into broad plates 

 and sometimes they are but delicate fibres. These meshes are 

 not stained with carmine or haematoxylin. As a rule, numerous 

 nuclei may be seen in the meshes. In the meshes of Microstoma 

 lineare, however, no nuclei are visible. The " Bindegewebszel- 

 len " are amoeboid cells which are scattered among the meshes 

 of the network and lie free in the perivisceral fluid which, 

 together with the amoeboid cells, fills the spaces in the net- 

 work. 



Bohmig ('90, pp. 197-206) discusses the parenchyme of Turbel- 

 larians in general. He says that the parenchyme of the forms 

 in this group is made up of two distinct substances : a Geriist- 

 substanz," which is arranged in a network, and which encloses 

 spaces or chambers of very different size and shape ; and a very 

 finely granular " Saftplasma " or " Hyaloplasma," which fills 

 the chambers of the network. He ('90, p. 200) says that these 

 spaces in the network are not entirely separate from one another, 

 and that the " Saftplasma " contained in them forms a continu- 

 ous mass throughout the whole body. Summing up, he ('90, 

 p. 205) says, " Das Parenchyme der Turbellarien besteht ur- 

 spriinglich aus individualisirten Zellen." He also states that the 

 manner in which these cells are modified to form the network is 

 different in different forms. In the Alloiocoels and a part of the 



