1901.] NATURAL SCIENCES OF PHILADELPHIA. 709 



layer is formed. The origin of these strands has been traced in 

 some cases to the circular muscle of the proboscis sheath, in other 

 cases to dorso -ventral fibres coming from the outer circular muscle 

 of the body wall. 



The change between the oisophagus and stomach is not only a 

 sudden but a very marked one (see fig. 33). Instead of the oesoph- 

 agus, with its low epithelium and its great extent of surface 

 caused by the high papillte, there is the stomach, without folds or 

 papillse and consisting of a very high epithelium, about four 

 times higher than that of the oesophagus, in which the large gland 

 cells are the principal element. The ciliated supporting cells, 

 S. C. , are present, apparently in equal numbers with the gland 

 cells, but are so small and inconspicuous that they are easily over- 

 looked. In fact, four specimens were studied before their presence 

 was detected, and they were seen for the first time in an over- 

 stained specimen, where the deep blue stain taken by their cyto- 

 plasm and their ciliary bases was in strong contrast to the pink of 

 the adjacent gland cells. 



The gland cells of the stomach, fig. 32, Gl.-i, are large, measur- 

 ing .087 mm. in height and .011 mm. in width. The distal end 

 is slightly narrowed into a neck, and the basal end into a slender 

 process that is inserted into the basement membrane, -B.il/. The 

 cell membrane is very distinct, and the cell body is filled with a 

 network of cytoplasm, in which are embedded large homogeneous 

 secretion globules that stain pink with eosin. Some slight color 

 differences seem to indicate difierent phases in the secretion, and a 

 few cells appearing lighter in color had evidently discharged 

 most of their secretion. The rather small oval nucleus, N., lies 

 near the base of the cell, not far above the basal process. 



Alternating with the gland cells are the small ciliated supporting 

 cells, fig. 32, S. C. They have a small cell body, about .004 mm. 

 in width, cm a very long stalk, *S'^., the basal ends of which are 

 inserted into the basement membrane. The cilia are short and 

 their structure could not be determined. A surface view of these 

 cells shows that there is one stout cilium in the middle of the cell, 

 while the other more slender ones ax'e arranged in a ring around 

 the periphery of the upper surface. The stouter cilium may occa- 

 sionally be seen in sections, and then appears slightly longer than 

 the peripheral ones. A few small interstitial connective tissue 



