SCIENTIFIC SUMMARY. 
311 
BOTANY. 
Tortula Sinuosa, in Warwickshire. — It may interest Bryologists to know 
that Mr. J. Bagnall has found this moss in Warwickshire, on the mortar 
of a brick bridge, near Wootton- Waven ; in this habitat small, apparently 
starved : also near Fenny-Compton, on an old tree-stump, the plants in this 
locality being robust ; in both habitats, however, barren. Pottia cavifolia 
is not confined to oolitic soils, as he found it abundantly on mud-capped 
walls, at Harbury, Fenny-Compton, Kineton, Wilnecote, and on marly 
banks at Bearley ; all these localities are on the lias, and are all in South 
Warwickshire. The forms he finds at Wilnecote seem to be typical, whilst 
at Harbury and the other localities the piliferous form appears to prevail. 
(See also “ Greviliea,” May.) 
j British Hepaticce. — 11 Greviliea ” says that the announcement that the 
first part of Dr. Carrington’s long-promised work is ready will be gratifying 
to some of our readers. It is uniform with the last edition of Sowerby’s 
“English Botany,” and is issued by the same publisher (Mr. Hardwicke, of 
Piccadilly). 
Measuring the Growth-rate of Plants. — Mr. E. Askenasy measures with a 
micrometer the advance of the growing-point of a root or branch in a glass 
tube in the field of the microscope. The stem is fixed by cork or other 
means at one end of the tube, and the conditions of light, temperature and 
moisture are easily regulated. 
The Fertilization of Gentians by Humble Bees. — The closed gentian 
( Gentiana Andrewsix) has flowers an inch and a quarter or more in length. 
These inflated, bright blue flowers of late autumn, appear to be always in 
the bud, as they never open. The corolla is twisted up so as to leave no 
opening at the top. The flowers are all nearly erect, with two stigmas con- 
siderably above the five anthers. The writer says he sees but one way in 
which it can be fertilized, that is by insects J but who the writer is we are 
not told. u Several of my students, as well as myself, more than two years 
ago, have often seen humble bees entering these flowers. They pry or un- 
twist the opening with their mouth organs and legs, and then pop into the 
barrel-shaped cavity, which they just fill.” 
The Structure of Fibre-cells. — Dr. B. Braithwaite is delivering before 
the Quekett Club a series of lectures on Vegetable Histology. The follow- 
ing are his observations on so-called fibre-cells : — u These are almost entirely 
confined to the vascular bundles, and hence are found in wood and bast 
tissue, but very rarely in pith or bark. They are distinguished by their 
great length, and touch each other on all sides, with more or less oblique 
faces, so that in outline they are fusiform, pyramidal or conical, and have 
very rarely any transverse partitions, but we find such in the branched bast- 
cells of Euphorbia. Fibre-cells are usually simple, and always more or less 
thickened, with the secondary and tertiary laminae distinct. The thicken- 
ing is greatest in bast tissue, and in it also the secondary layers are most 
distinct, those of wood-cells being more homogeneous, and pores are also 
usually present. A small wide-turning spiral band is seen near the bordered 
pores in wood-cells of yew,j vine, mezereon, Viburnum A Lantana , &c., and 
