JULY 1, Tor5\| 
NATURE 
491 

A xew addition to the list of British fishes is made 
by Dr. R. F. Scharff in the Irish Naturalist for June. 
This is the long-finned bream (Brama longtpennis) 
which was captured on May 18 last year, off the west 
coast of Valencia Island, Co. Kerry. Though bril- 
liantly coloured at the time of capture, by the time 
it had reached the island it had faded to a uniform 
grey hue. Only one other species of the genus has 
been recorded from Irish waters. This is Ray’s bream 
(Brama raii), which was recorded in 1888. To the 
same number Dr. Scharff contributes some interesting 
notes on Irish sharks. 
TuouGu observations on the birds attracted to light- 
ships and lighthouses during migration have been 
kept with much exactness during a number of years, 
no similar records had been made in regard to insects 
which in like manner are attracted by light, until 
recently, when the matter was taken up by Mr. W. 
Evans. The conclusion of his report on Lepidoptera 
and other insects at Scottish lighthouses appears in 
the Scottish Naturalist for June. It is usual, he re- 
marks, ‘‘to think of moths alone as night-fliers, and 
attracted by light, but . . . not a few other insects 
have similar habits, and are similarly attracted... . 
Both sexes come to the lanterns, but as a rule males 
predominate.” He also makes some interesting ob- 
servations on the dominance of certain colour varia- 
tions. 
ConcuoLocists will doubtless welcome the 
announcement of the rediscovery of Pourtales’s Hali- 
otis. This is made by Mr. J. B. Henderson in the 
Proceedings of the U.S. National Museum (vol. xlviii., 
1915). The first intimation of the occurrence of this 
genus in western Atlantic waters dates so far baclx 
as 1869, when a specimen was dredged up in the 
Straits of Florida. This was unfortunately destroyed 
in the great Chicago fire before it could be described. 
Twenty years later it was described from memory by 
Dr. Dall, who named it in honour of Count Pourtales, 
under whose supervision the original dredging opera- 
tions were carried out. Two years ago Mr. Hender- 
son, while dredging from the EKolis, along the inner 
edge of the Pourtales Plateau off West Key, in ninety 
fathoms, secured a second specimen of Haliotis, which 
proved on examination to be an immature specimen 
of the long-lost Pourtalesii. 
Tue reclamation of peat bogs is always a matter of 
economic importance, and the results achieved by 
sowing Pinus pinaster directly on a peat-bog, described 
in Irish Gardening for June, are worthy of wider 
notice. Two photographs are reproduced, one show- 
ing the depth of the peat where the seeds were sown 
in the west of Ireland, the other three of the young 
trees, four years old. The soil is fatal to the Scots 
Pine, but P. pinaster, if sown on the spot, thrives 
remarkably. The tree transplants badly, and for this 
reason the success attending the method adopted at 
Abbeyleix by Mr. Macgregor is very interesting. 
No. xxvii. of vol. vi. of Notes from the Royal 
Botanic Gardens, Edinburgh, for May, is occupied 
by a useful paper in the form of a key to the Labiatz 
of China, by Mr. S. T. Dunn. The key is based 
largely on the collections in the Hong Kong her- 
NO. 2383, VOL. 95] 
barium, and has been constructed on practical lines- 
Hong Kong being essentially the key to the botanical 
position as regards China, we welcome any work, 
based on the collections of that herbarium, tending 
to set out in orderly form the vast wealth of the 
Chinese flora as regards particular natural families. 
Even now it is not possible to arrive at a definite phyto- 
geographical survey of the empire as regards any one 
group of plants, but a key such as that just published 
is of value in helping forward the more detailed study 
of the flora of China. 
Tue condition known as Peloria, in which the ex- 
ceptional development of complementary irregularities 
make a typically irregular flower regular, is 
fairly commonly met with in  foxgloves and 
snapdragons under cultivation; indeed, in both 
plants a definite varietal form, with either 
the terminal or all the flowers peloric or regu- 
lar, appears to be fixed and to come true from 
seed. In the foxglove the variety is known as 
var. monstrosa, and the terminal flower is a more or 
less regular erect bell, similar to the flower of a Cam- 
panula. In Antirrhinum a varietal form has been so 
far fixed by Lorenz, of Erfurt, that 60 per cent. of 
the plants raised from seeds bear peloric flowers; this 
form is figured in ‘‘Gartenflora”’’ (1904, p. 113, 
t. 1524). Here all the flowers are tubular and per- 
fectly regular, but a form recently received from a 
correspondent resembles the foxglove, variety mon- 
‘strosa, in having the terminal flower only regular, 
with the characteristic lower lip of the snapdragon, 
forming a complete fringe round the actinomorphic 
tubular flower, while all the other flowers are zygo- 
morphic. A further peculiarity of these pleoric 
varieties is that the terminal flower of the raceme is 
the first to open, whilst in normal forms the terminal 
flower is the last to expand. 
HeLMHOLTz’s magnification formula of our elemen- 
tary text-books on optics is known to be a particular 
case of a number of interesting reciprocal theorems; 
for example, the property that.in a system of lenses 
the angular diameters of the object and image as 
seen from any position are inversely proportional to 
the linear diameters of the sections of the incident and 
emergent small pencils where they meet the eye. In 
the Atti dei Lincei, xxiv., 7, Prof. Levi Civita gives a 
general dynamical investigation of these reciprocal 
relations, including Straubel’s theorem, and with 
applications to multi-dimensional hyperspace. This is 
based on the analogy between trajections in dynamics 
and paths of rays, which analogy results from the 
principles of least action and time respectively. 
Tue rapid increase of the electrical resistance of pure 
iron with temperature makes it very desirable that 
the behaviour of iron resistance thermometers should 
be thoroughly investigated with a view to their intro- 
duction into common use. Such an investigation has 
been made by Messrs. G. K. Burgess and I. N. Kell- 
berg, of the United States Bureau of Standards, and 
the results are published in the May number of the 
journal of the bureau. The wire used was 99-98 per 
cent. iron, 0-24 millimetre in diameter, and 
} was wound on a porcelain insulator and enclosed with 

