172 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
b. Histology. 
Golgi Apparatus and Holmgren’s Trophospongium in Nerve-Cells. 
— Wilder G. Penfield (Anat. Record, 1921, 22, 57-80, 7 figs.). 
The Golgi apparatus has been described as a cytoplasmic constituent of 
all types of cells in the animal kingdom ; it has been observed develop- 
ing in the early stages of the embryo ; it has been seen to grow and 
divide with cell-multiplication. In neurones the apparatus reacts to 
axone section in a specific manner. There is no similar response on 
the part of Holmgren’s trophospongium. The two structures may be 
demonstrated independently in the cytoplasm of the same neurone, 
either successively or simultaneously. Occasionally there appears a close 
anatomical relationship between parts of Golgi’s apparatus and 
Holmgren’s trophospongium, which may indicate an intimate association 
of function. But the two structures are quite distinct. J. A. T. 
So-called Hibernating Gland. — A. T. Basmussen (Proc. Amer. 
Assoc. Anat. in Anat. Record , 1921, 21, 78-9). In marmots and the like 
it is clear that there is no histological resemblance between this structure 
and the thymus ; that there is no evidence of haematopoietic function ; 
that it is different from ordinary adipose tissue. The cells are rarely, if 
ever, unilocular ; the nucleus is never flattened much. The organ never 
loses all its fat. During hibernation it supplies only about one-thirtieth 
of the material consumed, so it is not an important food-reserve. The 
cytoplasm of the cell is rich in small granules (in addition to the fat 
globules), and the organ is surprisingly vascular. The “ hibernating 
gland ” remains a riddle. J. A. T. 
Structure of Small Intestine. — Eben J. Carey {Anat. Record , 
1921, 21, 189-215, 22 figs.). Because of the left-handed helicoidal 
arrangements of the musculature of the human intestine, the intestinal 
movements are comparable to the action of a left-handed screw. The 
inner muscular layer is wound as a close spiral. The outer is an open 
spiral. The difference in the rate of translatory progression in the two 
contraction waves depends upon this muscular arrangement. The wave 
travelling in the inner group of fibres takes a rotary course, whereas 
that in the outer fibres takes a more translatory course to reach a 
corresponding destination. Therefore, the contraction of the stronger 
inner muscle coat will inevitably trail that of the outer. The arrange- 
ment of the intestinal muscle layers clearly explains the phenomenon 
of cephalic constriction and caudal dilatation of diastalsis without 
invoking the aid of hypothetical nerve paths. Peristalsis, therefore, is 
a duplex contraction phenomenon produced by the differential rate of 
translatory advance of the two contraction waves in the outer and 
inner muscle layer respectively. J. A. T. 
Origin of Endothelium. — Charles F. W. McClure {Anat. Record , 
1921, 22, 219-37). Since endothelium is the essential tissue of the 
vascular system, the question has naturally arisen as to its origin in 
development. There are two opposing theories : {a) the angioblast 
theory of His, that the precociously developed vascular tissue (angioblast) 
of the yolk-sac grows into the embryonic axis and forms the whole 
