136 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
subject, in the case of some fruit-trees, especially varieties of the apple r 
pear, peach, and plum. Among the conclusions arrived at are the follow- 
ing : — One-year old fruit-bearing shoots of the apple and pear had less 
wood in proportion to their diameter than vegetative shoots of the same 
age. This is largely due to an increase of the cortex of the fruit-bearing 
shoot, which is also well supplied with supplementary mechanical tissue. 
In the peach, the fruit -bearing has more wood than the vegetative shoot. 
The effect upon the tissues is generally local. This local effect of fruit- 
bearing tends to an increase of cells, with a decrease in the thickness 
and lignification of the walls of the xylem-cells. In all cases the in- 
crease in growth is greatest on the side nearest the fruit-stalk. The 
local effect of fruit-bearing on the xylem-cylinder disappears with time. 
Fruit-bearing has a temporary local effect on the lignification of the 
walls of the xylem-cells, preventing it wholly or in part, according to 
their distance from the fruit-stalk. The lignification of other cell-walls 
is promoted by fruit-bearing. 
Fibrovascular Bundles of Nymphseacese.* — Further examples of the 
occurrence of several steles in the Nymphaeacese are given by Mr. D. T. 
G wynne- Vaughan, in the stalks or stolons which bear small tubers at 
their ends in Nymphsea flava and tuberosa. The tubers bear buds, which 
grow into fresh rhizomes, containing six or seven vascular bundles. 
Endoderm and Pericycle in Trifolium.t — Dr. S. Belli has made a 
very detailed study of the stele-theory in reference to the genus Trifolium. 
Histogenetic researches lead him to conclude that in Trifolium there is 
no pericycle in van Tiegliem’s sense. The elements referred to this 
layer belong to the bast and to the interfascicular cambium. A general 
endoderm and pericycle arc to be found only in the liypocotyl; after 
that disappears there is none. The memoir concludes with a general 
criticism of the stele-theory. 
Anatomy of the Stem of Macrozamia.J — Mr. W. C. Worsdell calls 
attention to the resemblances and differences in the structure of the 
stem of Macrozamia as compared with that of other genera of Cycadese. 
The pith possesses a well-developed network of vascular bundles similar 
to that of Encephalartos ; it has a distinct adventitious origin, and is not 
directly continuous with the primary leaf-trace system. The normal 
cylinder is surrounded by two or three anomalous zones of secondary 
thickening, the innermost of these being the best developed. The stem 
is characterised by the presence of a tertiary cambium, producing bundles 
with inverted orientation. In the abeve points the author points out 
the resemblance to the fossil group Medullosse. Other characters are 
referred to which are characteristic of the genus, viz. the presence of 
leaf-traces in the cortex, which run directly inward to the vascular rings 
after very short courses ; the structure of the girdles during their tan- 
gential course ; and the structure and mode of action of the periderm at 
the [periphery of the cortex ; the phelloderm being largely composed of 
stone-cells, and producing subsequently a second phellogen in its midst. 
* Ann. Bot., x. (1896) pp. 624-5. Cf. this Journal, 1896, p. 537. 
t Mem. R. Accad. Sci. Torino, xlvi. (1896) pp. 353-441 (6 pis.). 
t Ann. Bot., x. (1896) pp. 200-20 (2 pis.). 
