A STUDY OF RESTITUTION MASSES. 445 



were washed for a few minutes in water, passed quickly up through the 

 alcohols to 70*^0, and then washed for some hours in 70% alcohol, con- 

 taining a little hydrogen peroxide. After dehydration they were em- 

 bedded in paraffin and cut into sections 5yU thick. Heidenheiin's Iron 

 Alum Hsematoxylin, followed by Lichtgriin F.S. in 70% alcohol proved 

 a satisfactory stain for general purposes. 



Small restitution masses which were difficult to handle were sectionized 

 after previously mounting on a piece of amyloid liver, the mass being 

 made to adhere to the surface of the liver by means of a little albumen, 

 which was subsequently coagulated by alcohol. 



THE NORMAL TISSUES WHICH, AFTER DISSOCIATION, GIVE 

 RISE TO THE RESTITUTION MASSES. 



Antennularia ramosa is one of the Plumulariidse. It consists of shoots 

 which, springing from a single trunk at a certain height, divide and sub- 

 divide : the stems are thick and their branchlets are long and tapering, 

 having their internodes of equal length. The branchlets are closely set 

 and arranged in whorls where they come off the parent stem. The 

 Hydrothecse are small and campanulate in shape. Nematocysts are 

 present. The Gonothecse are pear-shaped and single ; and have a sub- 

 terminal aperture facing towards the stem. In healthy specimens the 

 perisarc is transparent and colourless, and the coenosarc is of a light 

 yellowish green tinge. 



Antennularia antennina consists of clustered stems, simple or slightly 

 branched, springing from a sponge-like mass of interlacing fibres. The 

 branchlets are short, swollen at the base, arranged in a whorl on each 

 articulation of the stem. They are divided by oblique joints into inter- 

 nodes, which are alternately larger and smaller, the former bearmg the 

 hydrothecse. The hydrothecse are small and campanulate in shape. The 

 Gonothecse are produced singly in the axils of the branchlets ; they are 

 oval, with a subterminal aperture looking towards the main stem. The 

 perisarc is transparent and colourless, and the coenosarc of a somewhat 

 brighter yellow colour than in the case of Antennularia ramosa. 



The coenosarc of both species is hollow, and consists of a tube of 

 cellular tissue in the walls of which a number of smaller tubes run in the 

 direction of the long axis of the stem. These smaller tubes are the direct 

 continuations of the enteric cavities of the individual hydranths, and 

 are lined with cells of a type similar to those forming the hydranths. 

 The whole arrangement is suggestive of that in a yomig dicotyledonous 



