1914] CURRENT LITERATURE 247 
in P. Merkusii this is less marked, while in P. Khasya there is no indication of 
such thickening. All three species contrast with the haploxylic Indian species 
in the feebler'development of the tissue separating the endodermis from the 
vascular tissue.” 
These structural ecological results are certainly very interesting, and 
Groom’s further contribution, which is already in the press, will no doubt add 
valuable results. It is very desirable that further studies be made on material 
where the ecological factors are definitely known, and also that a single species 
be studied ‘under its extreme of wet and dry conditions, in order to determine 
how much of the change is inherent in the species itself and how much is really 
due to the external conditions, 
The so-called “bars of Sanio” of the Harvard school come in for very 
severe criticism. They show that these are composed partly at least of pectic 
compounds, but not of cellulose. T hey also consider that Miss GERRY mistook 
SANIO’S description of trabeculae for these structures, and propose the term 
‘Sanio’s rims” for them, a.terminology which is certainly much more in keep- 
ing with Santo’s idea (“‘die Umriss des Primordialtiipfels”). Miss GERRY, 
however, made a much more serious mistake, for she even quotes SANIO’S 
description of the torus (‘diese scheibenférmige Verdickung”’) as referring to 
the structures in question. 
Resin plates were also found in some of the tracheids adjacent to the rays 
and also true trabeculae. The authors have also noted the presence of tracheids 
with bent ends: “when abutting on a medullary ray the end may fork, or bend, 
SO as to run for some distance along the ray and thus form a transition towards 
4 Tay tracheid.” They also found such tracheids forming radial series apart 
from the medullary rays 
The detailed description of the species is so arranged that easy reference 
can be had to any particular feature —R. B. THoMsoNn 
Some Jurassic plants—Among the pteridophytes described by THomas? 
from the Marske Quarry of the Middle Jurassic of the Cleveland district of 
Yorkshire is a new marattiaceous fern, Marattiopsis anglica. The genus is “a 
very common Rhetic and Liassic form, and has been recorded from Sweden, 
olm, Germany, Poland, and Tongking. Recently two incomplete 
leaflets from the Jurassic (Kimmeridge) beds of Sutherland have been placed 
by Sewarp in this genus. Allied forms from the Jurassic of Oregon have been 
described by Lester Warp and others under the old name of Angiopteridium.” 
# enclosing a number of loculi arranged in two rows; each loculus probably 
SRR 
_” THomas, Hucn Hamsnaw, The fossil flora of the Cleveland District of York- 
* I. The flora of the Marske Quarry. Quart. Jour. Geol. Soc. 69:223~251- 
bls, 23-26. 1913. 
