BOOK-NOTES, NEWS, ETC. 175 
The divergences } and } are often pretty Pages ee at the 
apex of vegetation; and the divergences 2, 3, and ;5, are some- 
times tolerably well realized on the grown-up parts of ‘ants ; but 
perceptible deviations therefrom are generally found on the 
appendages, and there a greater approximation to “ the limiting 
Leaves often occur in whorls; and alternating whorls are 
comparatively common. The num bers of leaves in a whorl — 
great diversities, nevertheless ~ 2-, 3-, we 5-numbered 
nating whorls are most frequen 
= illustrate the nen pp arran ement of crowded balls on 
, in the Acasa i the Royal Society, in 1873, 
nievaigl the followi wing experiment :—Take a number of spheres 
(say oak-galls) to represent Eabeyodaven, sad attach them in 
ios rows in alternate order (4) along opposide sides of a stretched 
india-rubber band. Give the band a slight twist to determine 
the direction of twist in the subsequent ee = then 
ae tension. The two rows of ie will be seen to roll up 
a strong twist into a tight complex order, which, if the 
splines are attached in close sora “wit the 
the order 4, with ee steep spirals. If the spheres are set a 
little away from the the order becomes condensed into nearly 
2, with great sei sia stability. It will also be seen that 
further contraction, with an increa: stance from the — 
necessarily produces, at least apprcitiinstaly, the orders 8, 35, 3 
&c., in succession ; and that these su successive orders represent suc- 
cessive maxima of stability, in the process of change from the 
simple to the complex. 
Again, in the Proceedings of the same Society of the following 
year, Airy showed, by other diagrams, that the same process of 
eouldbhsatiet n, operating on the or rders represented y the lower 
fractions of the series 4, 4, ?, 3, &c., will produce the higher 
orders of that series. The same is shown tot the series 4, }, 2, &c. 
Dr. Iterson draws attention to a. experiments. 
- Copious references are made to the works of previous writers 
on the subject, including German, Dutch, Russian, Hungarian, 
Italian, Swiss, French, and English authors. 
W. P. Hiern. 
BOOK-NOTES, NEWS, ¢e. 
Ar the meeting of the Linnean Society on 19th March, Mr. 
Hemsley sent for exhibition a specimen of Platanthera chlorantha 
with three spurs, found by Miss Susan Allett, of a per show- 
ing a spike each flower of which had ts e three 
a case of true peloria; the specimeén shown last year, aha figured 
in the Society’s + Jean l (Botany, Peevii, t. 1). had the three ot 2a 
spurred : a case of false peloria. Cav. has drawn atte: 
tion to the occurrence of true and false peloria i in - see in the 
2, ornate of — Mr. T. A. Sprague showed female 
