An Additional Record of Capria Nigra Piet (Plecoptera) . 199 
rows of long lignified parenchyma cells. At the time the 
interfascicular parenchyma cells begin to lignify a Casparian 
strip, which is not dissolved by concentrated sulphuric acid, 
forms on the radial walls of a ring of cells of the cortex next 
to the vascular bundles. This primary endodermis first 
becomes evident opposite the vascular bundles, but as the 
interfascicular parenchyma lignifies, it gradually spreads to 
a complete ring of cells around the stem. The primary 
endodermis and the lignified interfascicular parenchyma do 
not form in the higher internodes, nor at any of the nodes, 
and just above and below the oldernodes the Casparian strip 
is only seen in cells opposite the vascular bundles. 
Secondary elongation of the axis after normal cessation 
of growth causes renewed vascular differentiation throughout 
the stem. 
New xylem and phloem are differentiated in the old 
rhizome in late summer in connection with the formation of 
the new rhizome bearing next season’s shoot. 
References. 
1 Warming, E. Forgrenings forhold nos Fanerogamarne, 1-172 ; 
Copenhagen, 1872. 
2 Wight, W. ‘ Secondary Elongation Growth in Oaks, 1929/ The 
Naturalist, 65-70, 1930. 
3 ‘Yorks. Nat. Union Ann. Rep., 1927, Bot. Sect.’ The Naturalist, 
p. 153, 1928. 
4 Thoday, D. ‘ On the organisation of growth and differentiation in 
the stem of the Sunflower,’ Ann. Bot., 36, 489-510, 1922. 
AN ADDITIONAL RECORD OF CAPRIA NIGRA 
PIET (PLECOPTERA). 
G. A. NELSON : W. D. HINCKS (No. 33). 
On April ist we were fortunate in taking specimens of this 
interesting Stone-fly on the River Wharfe at Harewood Bridge. 
Two of the three males taken (one subsequently lost) were 
found under stones and the third was running on a sandy spit. 
Our efforts to find further specimens of these and of the 
females were totally unsuccessful. All were of the micropterous 
form with the wings reduced to merest rudiments. Morton 
(E.M.M., 1929, p. 133) records the occurrence of similar 
specimens but says that this condition has previously escaped 
notice. Whitehead (Nat., 1929, p. 405) has this species from 
V.C. 62 and 64 ; in the latter vice-county from River Laver, 
Galphey and Mean wood Beck, Leeds. The range of dates 
given is April 2nd to 16th. 
Further Note on Capria nigra. — A single female of this 
species was found by us on a later excursion (April 18th). 
This was taken resting on an exposed stone in a stream at 
Scarcroft. 
1933 Sept. 1 
