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SUMMARY OF CURRENT RESEARCHES RELATING TO 
Flagellate Thyroid Cells in Dogfish. — E. V. Cowdry (Anat. 
Record , 1921. 22, 289-99, 12 figs.). Each follicular cell in Mustelus 
canis has a large flagellum which extends into the colloid substance. 
They are well seen by Da Fano’s modification of Cajal’s silver method, 
but they may be seen in living thyroid follicles teased out in sea-water. 
Their presence indicates an interesting combination of motor and 
secretory functions without apparent adaptive value. It may, however, 
have some bearing on the problem of the ancestral origin of the gland, 
e.g. from the flagellated epithelium of a Tunicate endostyle. It also 
shows that the primary direction of the secretion is towards the follicular 
lumen, as claimed by Bensley, and not towards the peripheral blood 
vessels, as suggested by Norris. J. A. T. 
Influence of Inanition on Mitochondria of Gastro-intestinal 
Epithelium and of Pancreas— Shirley P. Miller (Ancif* Record , 
1922, 23, 205-10). Experiments on albino rats show that vitamin 
deficiency and acute starvation may produce changes in the mitochon- 
dria in the gastro-intestinal epithelial cells and in the gland cells of the 
pancreas. Asphyxiation does not apparently produce such marked 
changes. The amount of injury to the cell must be rather severe to 
bring about the changes observed. They may involve — (1) a transforma- 
tion of mitochondria from rod-like to spherical forms ; (2) an apparent 
reduction in the number of the mitochondria ; or even (3) the total 
disappearance of mitochondria from the cells. J. A. T. 
Endings of Cut Nerves. — Sydney M. Cone (Amt. Record , 1922, 
23, 185-6, 1 pi.). Cajal has not been able to demonstrate the 
regeneration of specialized end-organs of sensory nerves, but Cone 
describes the formation of Pacinian bodies (Yater’s corpuscles) in a 
finger stump. A capsule of vascular connective tissue encapsules the 
corpuscle. Several capillaries of a fasciculus of nerve fibres pass into 
corpuscle and spread at the periphery. The nuclei of the Schwann 
sheath cells become even more than ordinarily elongated and flattened 
at the circumference, but three or four entire cells are demonstrated in 
the central core. J. A. T. 
Is Mesenchyme a Syncytium ? — Warren H. Lewis (Anat. Record , 
1922, 23. 177-84, 4 figs.). Many histologists regard the mesenchyme 
as a syncytium. They believe that there is actual fusion of process with 
process, continuity of cytoplasm, and absence of cell boundaries. A 
study of embryonic chick material of various organs and tissues has led 
Lewis to the conclusion that embryonic mesenchyme is not syncytial in 
structure. The evidence from tissue cultures points to the conclusion 
that it is an adherent reticulum or network. J. A. T. 
Hematomas in Heart Valves of Calves. — Laura Florence 
{Amer. Journ. Diseases Children , 23, 1922, 132-8). Hematomas and 
haemorrhages are of frequent occurrence in the atrioventricular valves of 
human foetuses and of young calves. They occur in the region of 
attachment of the chordae tendineae, and both may occur in the same 
valve. The hematomas are subcircular cavities lined with a single layer 
