518 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Structure of Ophioglossum.* * * § — M. G. Poirault calls attention to two 
or three points in the structure of Ophioglossum vulgatum. The vascular 
bundle of the root possesses only a single phloem-structure. The only 
anomaly of the root of Ophioglossum is the absence of a pericycle at the 
back of the phloem-bundles ; and this occurs also in the stem. In the 
leaf the layer of cells surrounding the outermost sieve-tubes must be 
regarded as an endoderm. The formation of adventitious buds on the 
root does not result from the transformation of the radical cone into a 
leafy stem ; the bud, on the contrary, has a lateral origin, and grows at 
the expense of a portion of the segment cut off from the mo her-cell of 
the root. The bud is not always a ramification of the mother-root ; it 
may have an endogenous origin in the cortex of the stem below the zone 
where the roots are formed. 
Tubercles of Equisetum.f — According to M. Leclerc du Sablon, 
the underground tubercles of Equisetum maximum differ in several points 
of structure from the rhizome. The epiderm is but very slightly 
differentiated. In addition to the general endoderm of the vascular 
cylinder, each bundle in the tubercle has its own special endoderm, — a 
characteristic of the vascular system of the stem of some other species 
of Equisetum , e. g. E. arvense , palustre, and sylvaticum, but not of that of 
E. maximum. The vessels of the xylem are spiral and annular, are 
smaller and more numerous than in the rhizome, are irregularly dis- 
posed, and not in the form of a Y, and have no lacuna on the inner 
side of the bundle, as is the case in the rhizome when mature. The 
tubercles of Equisetum sylvaticum agree in essential points with those of 
E. maximum. 
Fossil Remains in the Culm 4 — Prof. Graf zu Solms-Laubach de- 
scribes the fossil remains found in the calcareous deposits of the Culm 
at Glatzisch-Falkenberg in Silesia. They abound in Stigmaria ; and the 
author finds also some hitherto undescribed forms. He describes one as 
Zygopteris Romeri, belonging, from the anatomy of the leaf-stalk, to a 
different type from the hitherto described Z. tubicaulis. Fragments of 
fern-roots and branches of Lepidodendron were also found, as well as 
fern-sporanges. 
Muscinese. 
Anatomy and Physiology of Mosses. § — Herr P. Coesfeld has 
studied several points in the structure of Mosses, especially of Poly- 
trichum commune. The elongated cells of the central bundle acquire 
their form by stretching, the nucleus at the same time changing from a 
round to a spindle-form and finally disappearing. Of the entire tissue of 
the stem of Polytrichum , this central bundle alone gives a pure cellulose 
reaction ; neither in the central bundle nor elsewhere did reagents give 
any evidence of lignification. The cells of the bundle contain (in 
March) oil and starch-grains. The bundle is sharply marked off from 
the cortical tissue by a protecting sheath. The cortical tissue consists 
* Journ.de Bot. (Morot) vi. (1892) pp. 69-76(1 fig.). Cf. this Journal, 1891, 
p. 500. 
f Rev. Gen. de Bot. (Bonnier) iv. (1892) pp. 97-101 (6 figs.). 
x Bot. Ztg., 1. (1892) pp. 49-56, 73-9, 88-98, 105-13 (1 pi.). 
§ Tom. cit., pp. 153-64, 169-76, 185-93 (1 pi.). 
