No. 3.] ORGANS IN PHASCOLOSOMA GOULD!/. 387 



in which the different cells show varying phases of activity. 

 While in most of the cells the contents appear finely granular, 

 in one the secretion is formed into spherules, and these spher- 

 ules I believe to represent a very late stage in the activity of 

 the cell. 



Oj'gans of the Second or Glandiilar Class {Second Type). 



This type, by far the most interesting of the four classes, 

 includes certain large glandular organs characterized by the 

 presence of some remarkable intracellular canals within the 

 gland cells. These organs are found abundantly in all parts 

 of the body of the worm, with the exception of the anterior 

 portion of the proboscis. In the region of the nephridial open- 

 ings and the anus they are the most common of the four types, 

 as many as ten different organs often being shown in a single 

 section. Fig. 16 (PI. XXXV) represents a section through 

 one of these bodies, and shows that, as in case of the other 

 three classes, a thin membranous sack encloses the whole 

 organ, which contains at least two types of cells, viz., gland 

 cells and sense cells. By ordinary methods of preparation the 

 sense cells would probably escape notice entirely, but by the 

 use of the blue stain they are rendered conspicuous, the gland 

 cells as a rule remaining entirely unstained. Figs. 9 and 12 

 (PI. XXXIV) are drawings from methylene-blue preparations. 

 As figured here, the sensory cells are bipolar and resemble in 

 some respects those of the fTg^st type of glandular organ, the 

 peripheral and central processes being both very slender. The 

 peripheral endings are similar to those found in the non-glan- 

 dular organs, for at a little distance below the cuticula the ex- 

 ternal process of the cell shows an expansion, and from this 

 expanded end a sense hair ascends to the cuticula and passes 

 through it to the exterior. The long axes of the cell bodies 

 are, as a rule, nearly vertical to the cuticula, and the central 

 processes either take a course perpendicular to the ring muscle, 

 through the middle of the organ, or else lie close to the mem- 

 branous covering of the organ, the processes seeming, as it were, 

 to creep over the gland cells. In sections of material prepared 



