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PROFESSOR J. STEPHENSON AND DR BAINI PRASHAD ON 
Vascular Supply of the Glands. 
The large vessel in the dorsal edge of the vertical wall (fig. 10) has already been 
mentioned ; it is continued back behind the level of the glands for some distance in 
the oesophageal wall before it disappears in the general gut sinus. 
There is also a sinus in the vertical partition (not visible in fig. 10), which com- 
municates on the one hand with the vessel just mentioned, and on the other is 
continuous with the sinuses in the lamellae. These latter are potential or actual, 
according as the part of the gland is engorged or empty of blood (fig. 9) ; they 
separate the two layers of epithelium of which the lamellae are composed. These 
lamellar sinuses become, at their peripheral margins, a series of circular sinuses in 
the oesophageal wall. Leading off from the front end of the glands is a vessel on 
each side which lies in the lateral wall of the oesophagus. The whole organ is thus 
permeated throughout with blood. 
The Epithelium of the Glands. 
(a) On the Lamellae. — In the average condition the cells are approximately cubical, 
about 10 y in height, and each projects as a low rounded, dome-shaped swelling into 
the interlamellar space. The nucleus is rather superficial, usually in the dome-shaped 
swelling ; it is roundly ovoid, 5—6 /x in long diameter, with scattered granules of 
chromatin, and one larger darklv-staining particle. 
The surface of the cell is often seen to be disintegrating, and then may best be 
described as shreddy ; here and there long cilia-like threads are given off from the 
surface ; the resemblance to cilia may be very close (some acid-fixed preparations). 
The epithelium appears for the most part as a single layer ; but in places a number 
of superficial cells are seen, which appear to be disintegrating in toto — staining only 
very lightly, and being thrown off along with their nuclei. In addition, small solid 
crystal-like particles are being produced and thrown off in certain regions, or in 
certain preparations (fig. 9). 
The epithelium of neighbouring lamellae is continuous round both the external 
and internal ends of the interlamellar spaces. 
In well-fixed preparations a basement membrane is often not to be made out ; 
it is best seen in badly-fixed specimens (fixed without opening the worm) where 
acid fixatives have been used (Zenker’s fluid). Here the glands are in places 
skeletonised ; the epithelial cells have become detached, and the basement membrane 
is left to indicate the position of the lamellae ; the membrane may appear as a single 
or double layer in each lamella — potentially double, no doubt, throughout, and 
corresponding to the two layers of epithelium which compose the lamella. 
Between the two layers of cells there are seen numerous nuclei, much flattened 
or of an elongated ovoid shape. A number of ovoid or rounded nuclei are also 
contained in the deeper portions of the epithelial cells themselves. 
