274 
given if only for the benefit of those who like to make 
gorgeous preparations. 
A small book on “ Microscopical Manipulation,” well 
up to the time, would be useful to students. We are sure 
Mr. Suffolk does not wish to claim this position for his 
digest of the older handbooks, His excuse for its publi- 
cation must be that in this country there are many people 
who indulge in the expensive peepshows sold by our 
English opticians, to whom it will really be acceptable. 
It must not be imagined that we for one moment ob- 
ject to such amusements ; on the contrary, they are alto- 
gether to be commended where more serious work cannot 
be undertaken—and only then. IDI iby 
Notes of a Season at St. Moritz in the Upper Engadine, 
and of a Visit to the Baths of Tarasp. By J. Burney 
Yeo, M.B. (London: Longmans, 1870.) 
WE commend this sensibly-written and interesting little 
book to the notice of our readers, many of whom, notwith- 
standing the outbreak of hostilities between our friends 
across the Channel, may yet seek health and enjoyment 
in these remote valleys, where it is in the highest degree 
improbable the tide of war will ever roll. Dr. Yeo’s little 
brochure contains all that it is necessary the intending 
tourist need know, and much that the invalid ought to 
know before starting for the Upper Engadine. To the latter 
class of travellers in particular it is of no slight importance 
to know the nature of the lodging and food they can 
obtain, and the advantages to be gained from a residence 
in a new and untried region ; and upon these points Dr. 
Yeo’s experience enables him to speak with much confi- 
dence. St. Moritz, it must be remembered, is 6,000 or 
7,000 feet above the level of the sea, and the air, though 
bright and clear, is by no means warm. ‘The waters con- 
tain a small proportion of iron, and are strongly charged 
with carbonic acid, which may perhaps act as a stimulant 
both to the skin and the stomach in tolerably healthy 
patients ; but Dr. Yeo makes some judicious remarks on 
their effects on those who are debilitated and exhausted, 
and the advantages resulting from leaving off the pre- 
scribed cold bath, and glass or glasses of cold water. The 
last chapter contains a capital account of the Fauna and 
Flora of St. Moritz and Tarasp, the latter embracing 
between 300 and 4oo plants, arranged according to their 
natural orders. 
Reactions-Schema fiir die qualitative Analyse, zum Ge- 
brauche int chemischen Laboratorium zu Berlin. (Ber- 
lin, 1870. Verlag von August Hirschwald. London: 
Williams and Norgate.) 
Tuis is a kind of pictorial analytical table in which the 
characters of the precipitates obtained are indicated by 
coloured oblong spaces, which will, doubtless, be found 
very useful for impressing the appearances of the different 
precipitates on the mind of the student. ‘The borax bead 
obtained with a compound of cobalt is represented by a 
blue oval, and the effect of ammonia on red litmus paper 
is shown by an oblong half red and half blue. The 
changes of colour produced by the action of sulphuretted 
hydrogen on a salt of mercury are indicated by an oblong 
of four different colours, white, yellow, orange, and black. 
It is unfortunate that this table is not more complete ; 
thus no means of obtaining the solution to be treated is 
mentioned ; the destruction of organic matter before pre- 
cipitation by ammonia and ammonia sulphide is omitted ; 
the possibility of the precipitate in the third group con- 
taining phosphates, and the mode of examining it under 
such circumstances, is passed over entirely. The spectra 
of potassium, sodium, and lithium, are indicated by black 
lines with fine transverse white ones, representing the 
coloured bands, but unfortunately no means are given to 
show which is the more refrangible end of the spectrum. 
Besides these omissions there are some misprints which 
will no doubt be corrected in a subsequent edition. 
NATURE 
[Aug. 4, 1870 
LETTERS TO THE EDITOR 
The Editor does not hold himself responsible for opinions expressed 
by his Correspondents, No notice is taken of anonymous 
communications. | 
Fertilisation of Polygala 
HAs the method of fertilisation of the milkwort, Polygala 
vulgaris, yet been described ? It presents one of the most beauti- 
ful contrivances with which I haye hitherto met for securing a 
cross through the agency of insects. The corolla consists of five 
petals united into one piece and folded into the form of a two- 
lipped tube, the upper lip of which is formed by the over-lapping 
edges of the corolla ; while the lower lip is a somewhat cup- 
shaped appendage (c), furnished with a ‘‘ beard” of gland-like 
bodies (4), and opening in front by a narrow, vertical slit. The 
filaments of the stamens are united throughout the greater part 
of their length with the corolla, but expand within the cup 
of the lower lip into a two-lobed membrane, crowned by the 
anthers (a). The pistil has two stigmas, one of which (s) is 
placed at right angles to the upper side of the style and is perfect , 
while the other (s’) is transformed into a spoon-shaped, petaloid 
prolongation of the pistil, reaching to the opening of the lower 
lip of the corolla, and dividing the interior of the flower into 
two chambers, in the lower of which are the stamens, thus com- 
pletely separated from the true stigma. The entrance to the 
flower, below the style and in front of the stamens, is closed by 
hairs pointing outwards from the flower and meeting in front, 
on the mouse-trap principle ; but a narrow passage is left open 
above the petaloid stigma, and is perhaps capable ofa slight dis- 
tension from the flexibility of the overlapping petals. On each side 
of the interior of the tube of the corolla, above the style and just 
behind the true stigma, is a group of streng, white hairs (2), 
pointing down the tube of the corolla, and meeting above the 
style. If we now suppose a smail insect to light upon the 
‘“beard ” of the flower, it is prevented from immediate entrance 
by the projecting hairs, but soon finds the narrow passage lead- 
ing over the stigma into the upper chamber, It is prevented by 
the hairs in the tube of the corolla from returning by the same 
path, and is obliged to crawl out through the lower chamber 
and over the stamens ; pollen from which it will, by a repetition 
of the same process, convey to the stigma of the flower next 
visited. 
In the bud the anthers are in contact with the stigma, and 
some caution is necessary in dissecting that they may not be 
crushed, giving the appearance of the pollen having been de- 
posited e7 masse on the spoon-shaped stigma. Naturally, I 
believe, the pollen is neyer shed till after the complete expansion 
of the flower. 
I have never actually observed any insect either in the flower 
or sucking nectar from it, but I have almost invariably found a 
few small ,black flies upon the bunches that I haye brought in for 
examination. 
The broad and conspicuous ‘‘ wings” of the calyx having ful- 
filled their office of ‘‘ tempting insects to their food,” gradually 
assume the green colour of the ordinary leaves, and closing over 
the ripening capsule, serve probably to conceal and protect it 
from the attacks of some enemy. 
Kilderry, Co. Donegal W. E. Hart 
P.S.—I have to record a similar phenomenon with respect to 
the holly berries of this neighbourhood to that mentioned by 
Mr. Henry Reeks (NATURE, June 9). I did not remark that 
any varieties in particular had been rejected ; but few that bore 
fruit (of which there was a much greater quantity than usual) 
appeared to have lost any of it, so late as the end of May, And 
yet we had not fewer of the migratory thrushes than in former 
years, when the holly bushes were generally stripped of their 
berries before the end of January; and, on the other hand, 
we had several days of frost, extraordinarily hard for this 
neighbourhood. On what arguments does Mr, Reeks ground 
his presumption, so different from Mr, Darwin’s own con- 
