626 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
gams and Phanerogams, two primitive types of vascular axes, — the 
prostelic type, consisting primarily of a single concentric bundle, and 
the si phono stelic, in which the vascular tissue forms, from the outset, a 
bundle-tube. These latter are again distinguished into phyllosi phonic 
and cladosiphonic ; in the former the continuity of the vascular bundle 
is interrupted by lacunae occurring above the points of exit of the leaf- 
traces ; in the latter the lacunae occur above the traces of the branches. 
The archegone of the Equisetaceae resembles that of the isosporous 
Lycopodiaceae in being uniformly without a basal cell, which is invari- 
ably present in the archegone of the isosporous Filicales. Another 
agreement with Lycopodiaceae is the fact that both shoot and root 
originate from the upper (epibasal) region. 
As a general conclusion, the Equisetales appear to be related to the 
Lycopodiales rather than to the Filicales, especially in the following 
points : — garnetophyte with fleshy vertical axis and thin lateral lobes ; 
archegone without a basal cell and with vertical division of the neck- 
canal-cell ; root and shoot epibasal in origin ; small leaves and strobili ; 
cladosiphony. 
As regards fossil forms, the Sphenophyllaceae must be regarded as 
the protostelic ancestors of the Equisetales, agreeing with them closely 
in all particulars except the structure of the stele. 
Muscineae. 
Apical Growth, Phyllotaxis, and Origin of the Branches in 
Mosses.* — Herr C. Correns adds two more examples to those already 
known of the apical cell in Mosses dividing into two instead of three 
segments. In other Mosses this also occurs occasionally on special 
branches. The permanent phyllotaxis is ascribed by the author to 
secondary lateral displacement of the segments, resulting in a mode 
of torsion which he terms “ apical torsion.” It appears to be dependent 
on the supply of light. The origin of the branches in acrocarpous and 
pleurocarpous mosses is next discussed. In many cases the lateral 
branches arise at regular intervals determined by the number of divi- 
sions in the apical cell ; while in other cases there are a large number 
of barren segments between two branches. Species of the same genus 
present no uniformity in this respect. This also appears to be to a 
certain extent dependent on light. 
Classification of Hypnacese.t — Herr G. Roth proposes to break up 
the Hypnaceae into five distinct orders, viz. : — (1) Isotheciacese, with 
four groups, — Lescuraeae ( Lescursea ) ; Cylindrothecieae ( Platijgyrium T 
Pylaisia, Cylindrothecium ; Orthothecieae ( Orthothecium ) ; Isothecieae 
( lsothecium , Homalothecium). (2) Brachythecicicese , with two groups : — 
Brachystegias ( Camptothecium , Ptychodium , Brachythecium , Scleropo- 
dium ) ; Eustegiae ( Bryhnia , Bhytidium , Myurium, Eurhynchium , Bhyncho- 
stegium , Bhynchostegiella). (3) Amblystegiacese (. Amblystegium , Crato- 
neuron , Campylium, Drepanocladus , Calliergon). (4) Hypnacese , with 
two groups : — Plagiothecieae ( Plagiothecium , Isopterygium, Bhaphido- 
* ‘Ueb. Scheitelwachsthum, Blattstellung, u. Astanlagen d/Laubmoosstamchens/ 
Berlin, 1899, 28 pp. and 8 figs. See Bot. Ztg., lvii. (1899) 2 te Abt., p. 241. 
t Hedwigia, xxxviii. (1899), Beibl., pp. 3-8. 
