NOTES AND ABSTRACTS, 
525 
Formula II. 
Rain-water ...... 1 litre 
American potash . . . . . 10 or 12 grammes 
Sulphoricinate of soda .... 40 „ 
Tobacco juice ..... 20 „ 
Spirits of wine ..... 20 
At this period the eggs of the aphis are laid in the cracks of the tree, and to 
destroy these M. Duval advises the application of the following mixture at about 
the end of October : — 
Formula III. 
Rain-water ....... 1 litre 
Soft soap . . . . . . 350 grammes 
Sulphoricinate of soda . . . . . 50 
Finally, open a hole all round the tree so as to uncover the roots, and water these 
with Formula I. or, if necessary, Formula II. — M. L. H. 
Worms, Enchytraeid, The Action of. By Rev. H. Friend (Ann. Appl. 
Biol. iii. p. 49; June 1916). — Experiments made by the author with white 
worms, and also with some species of the same group with red blood, all common 
in soil containing much decaying vegetable or animal matter, convince him 
that they are scavengers doing no damage to cultivated plants. — F. J. C. 
Xerofotic Movements in Leaves. By Frank C. Gates (Bot. Gaz. lxi. p. 399 ; 
8 figs.). — The author begins by defining xerofotic, but why it is not spelled 
xerophotic we do not know ; there is no f in Greek. It signifies " dryness 
caused by light." The movements " are manifested by an upward bend in 
the leaflets, or a curling or rolling upward of the blade." 
With regard to the mechanism : " The side of a structure facing the sun 
becomes warmer than the opposite side . . . hence there is a greater loss of 
water from the exposed side . . . the greater turgidity on the lower side causes 
the leaf -blade to bend in the direction of the exposure. 
" Two kinds of xerofotic response were observed : the localized response, it 
which the differential turgidity is largely confined to a small region, as the 
pulvini ; and the generalized response, in which it is spread over the leaf, causing 
the blade to curl upward." 
The article deals with the localized, specially observed in leguminous plants. 
The xerofotic position is between 45 0 and 70 0 from the horizontal. The move- 
ment is not peculiar to any season. 
" The obvious result of the xerofotic position is to decrease the amount of 
direct radiant energy received per unit area of leaf. When screens were placed 
before plants in the sun, the leaflets fell back to the horizontal position. 
" In successive experiments, both absolute alcohol and xylol were carefully 
applied to the upper side of the pulvinus with a small pointed brush. As the 
"drying agent withdrew water locally from the upper cells of the pulvinus, the 
xerofotic position of the leaflet was gradually assumed." 
The generalized type was noted particularly on monocotyledons, which have 
no pulvinus. — G. H. 
Yellow Pine Needle Disease. By J. R. Weir (Jour. Agr. Res. vol. vi. No. 8, 
May 1916, pp. 277-288; 1 plate, 4 figs.). — A very conspicuous disease on the 
needles of the Western Yellow Pine (Pinus ponder osa Laws.) has been observed 
in parts of the States of Montana, Oregon, Washington, and Idaho. The causal 
organism is a new species and has been named Hypoderma deformans. The 
first sign of infection is a slight browning of the tips of the leaves, which soon 
becomes a yellow, deepening into a brown colour when the apothecia appear. 
Owing to the attacks of this fungus, the terminal shoots become distorted 
and stunted, eventually forming " witches' brooms." 
Attempts to grow the fungus upon culture media were without success. — A . B. 
Zygopetalum Prainianum (Bot. Mag. tab. 8610). — Peru. Nat. Ord. Orchidaceae. 
Tribe Vandeae. Herb, terrestrial. Leaves elongato-lanceolate, 10-14 m - ^ong. 
Scapes 2 ft. long, 4-5-flowered. Flowers 2 in. across, sepals brownish-green, 
petals white ; column incurved, yellow. — G. H. 
