352 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
formation occurs in less salt lagoons and bogs which are only reached by 
the highest floods. The characteristic species is Nipa fruticans. The 
Barringtonia formation, consisting chiefly of species of that genus of 
Myrtaceaj, is characteristic of more sloping coasts. The Pescaprae 
formation, represented characteristically by Ipomaea pes-caprse, consti- 
tutes the sparse flora of the sand-dunes. 
A marked feature of all these plants is the facility with which they 
absorb and store up chlorides in their tissues ; this is especially charac- 
teristic of certain herbaceous orders, such as Plumbaginaceae, Cheno- 
podiaceae, and Frankeniacese. Protection is further provided against 
excessive transpiration by the smaller surface and greater thickness of 
the leaves. 
Inversion of Organs or Tissues.* — Dr. M. T. Masters describes a 
number of cases in which organs or elements of tissue exhibit a position 
inverse to that w r hich they normally occupy, viz. : — Reversed position 
of the xylem and phloem-elements (fruit-scales of Coniferae, where the 
relative positions of the xylem and phloem are the reverse of that found 
in the bracts) ; palisade cells (leaves of Picea ajanensis , where the 
palisade cells are on the dorsal or under, the stomates on the ventral 
or upper surface) ; stomates (adult leaves of juniper and Picea ajanensis , 
cladodes of Ruscus androgynus ) ; the flower (abnormally in Cypripedium , 
Gladiolus, and barley) ; carpels (abnormally in Citrus, Crataegus, Prunus, 
&c.) ; gills of fungi (not unfrequent in species of Agaricus , especially 
the mushroom). 
Structure of Witch-broom.f — Herr T. Hartmann describes the ana- 
tomical structure of the witch-broom of the silver fir. The following 
are the chief points of difference from the normal structure of the leaves 
and branches. The leaves have fewer stomates and a thinner cuticle ; 
the resin-passages are smaller ; the parenchyme-cells contain less starch 
and chlorophyll, and there are fewer cells with bordered pits. In the 
diseased branches the periderm is less strongly, and the cortical paren- 
chyme more strongly developed ; there is a much larger quantity of 
pith ; the annual rings are less strongly developed. 
£. Physiology. 
Cl) Reproduction and Embryology. 
Embryo-sac of Aster and Solidago.J — Mr. G. W. Martin has traced 
out the development of the flower, and especially that of the embryo- sac, 
in these two genera. The calyx appears second in order of succession 
of the floral whorls. The syngenesious anthers are united structurally 
in their origin. The ovule does not arise from the bottom of the ovarian 
cavity, but a little above the lowest point ; it is, therefore, not a direct 
outgrowth of the axis, but an outgrowth of the leaf. In its early deve- 
lopment the nucellus is almost orthotropous, and gradually becomes 
anatropous by greater growth on one side. The embryo-sac consists 
* Journ. of Bot., xxxi. (1893) pp. 35-40 (5 figs.). 
t ‘ Anatom. Yergleich. d. Hexenbesen d. Weisstanne u.s.w.,’ Freiburg i. B., 1892, 
39 pp. and 1 pi. See Bot. Centralbl., 1893, Beih., p. 60. 
+ Bot. Gazette, xvii. (1892) pp. 353-7, 406-11 (2 pis.); and Amer. Natural., 
xxvi. (1892) pp. 954-7. 
