478 
PROFESSOR J. STEPHENSON AND DR BAINI PRASHAD ON 
being fused at their bases ; in a secretory cycle the protoplasm at first increases, so 
that the cells project as club-like processes ; lime granules appear in the interior, the 
cytoplasm degenerates and the granules are thrown out ; the cytoplasm in the cell 
projections is nearly all used up, and if there has been over-secretion the cytoplasm 
disappears almost down to the blood sinus ; — “ in its lowest terms . . . the secreting 
layer is very thin, and may be reduced ... to the thickness of an ordinary blood- 
vessel scarcely the width of the nuclei which are embedded in it” (the meaning 
is not very clear). The nuclei also collapse or become cast out into the gland cavity 
during active secretion, exhaustion of the nucleus running parallel to exhaustion of 
the cytoplasm ; indeed nuclei may be scarcely visible through loss of staining power, 
and may be distinguishable only by the inconspicuous nuclear membrane. 
Now comes the peculiarity of Harrington’s position. The nuclei are replaced? 
by others which migrate from the blood sinus into the glandular layer ; nuclei are 
seen in every possible position between partial and complete embedding in the 
glandular syncytium ; “ repeated observations have demonstrated beyond a doubt 
that these wandering cells or migratory nuclei are constantly and normally making 
their entrance into the gland cells at certain periods of the gland’s activity.” These 
migratory nuclei are attended by a thin protoplasmic film ; they may be of the most 
extraordinarily elongated forms ; the cytoplasm which is brought in fuses with the 
general syncytium, and the nuclei then become the typical nuclei of the glandular 
layer. Thus what happens is that “ wandering cells migrate into an enlarged 
blood-vessel wall and undergo degeneration, during which the accompanying cyto- 
plasm expands and is finally transformed into lime crystals.” 
And again: “The cells, which here replace the waste caused by secretion, are 
derived from the walls of the blood-vascular system. The unusual relations between 
the glandular and circulatory systems can be interpreted only by regarding the 
one-layered secretory lamellae bounding the blood spaces as greatly hypertrophied 
vascular walls representing both the intima and endothelium.” 
The follicles are therefore an enlarged blood-vessel wall. It is true that the 
germ-layer theory seems to stand in the way ; but according to Harrington’s 
observations, the earliest blood corpuscles in the embryo, as well as the follicles 
themselves, are derived from the mass of yolk cells surrounding the cavity of the 
gut, and hence corpuscles and follicle cells have the same ultimate origin. 
Such is Harrington’s conception of the glands. In criticism it must be 
remarked that unless “an enlarged blood-vessel wall” is used in a sense very 
different from the usual one, the expression is wrongly applied to the follicular 
epithelium. In cases where a vascular endothelium has been described, it is a layer 
of naked cells lying on a basement membrane, outside which again is the muscular 
(or muscular and connective) coat of the vessel ; here the basement membrane 
would be the innermost layer, and the endothelium would be outside this. But 
that the follicular epithelium cannot be anything to which the term blood-vessel 
