260 
NATURE 
[May 9, 1912 
alone, that is, without the addition of heated serum. 
But if fresh venom were mixed with glycerine and 
filtered through filter-paper, the results were similar 
to those of Briot; they were, however, different if a 
Berkefeld filter were used instead of filter-paper, just 
as the action of liver extract is affected according as 
it is filtered through cloth or through filter-paper. 
Dr. Evans then described the conclusions of Porta, 
from examination of sections of the spine of the sting 
ray (Trygon pastinacea), conclusions which had been 
disputed by Pawlowsky, who stated that Porta had 
confused glandular tissue with deformed blood- 
corpuscles, and denied that poison. glands with 
groups of small cells existed in the spine of Trygon. 
By photomicrographs Dr. Evans then showed not 
only that Porta’s triangular glands existed, but that 
they were only part of a large system present through- 
out the whole spine. The latter was described as 
consisting of (1) an intracaudal portion, of bony mesh- 
work, containing round-celled glandular tissue and 
masses of secretion surrounded by flattened cells; (2) 
an intermediate portion with the ventral ridge still 
embedded in the tail, with gland follicles either 
radiating towards the convex surface or running 
longitudinally in the ventral prominence; formed 
secretion can be seen leading into the lateral grooves; 
(3) the free portion with the triangular glandular 
masses of Porta, and cavities occupied by small-celled 
tissues and formed secretion; towards the tip of the 
spine these become three, one in each lateral portion 
and one in the ventral ridge. The hamolytic proper- 
ties of these venoms were described, and in the 
ensuing discussion the painful toxic effects of the sting 
were described by one speaker from personal experi- 
ence. 
MANCHESTER. 
Literary and Philosophical Society, April 2.—Prof. 
F. E. Weiss, president, in the chair.—J. Mangan: The 
presence of Maxillula in larvze of Dytiscide. It was 
shown that in this family of water-beetles the mouth 
of the larval form is armed with a pair of strong 
processes, at the base of the mandibles, which appear 
to be homologous with the maxillulze or superlinguz 
of certain primitive insects.—Prof. W. H. Lang: The 
interpretation of the vascular anatomy of the Ophio- 
glossacee. The author described the anatomy of the 
stem and leaf-trace of rhizomes of Helminthostachys 
of various ages; and the progression of the stele 
towards the mesarch condition was followed. The 
occasional development of accessory or secondary 
xylem was recorded. The distribution of the tissues 
in the stele was compared with that in the stele of 
Zygopteris, the centripetal xylem in Helminthostachys 
being regarded as corresponding to the inner xylem 
of Zygopteris. The departure of the leaf-trace also 
exhibits points of resemblance. The occasional 
development of centripetal tracheids forming a mixed 
pith was described for Botrychium lunaria and Ophio- 
glossum, sp. The pith of the Ophioglossacez appears 
to be of intrastelar origin and not due to intrusion 
of cortex. Ophioglossaceze and Ccenopterideze appear 
to throw mutual light on one another as regards 
morphological and anatomical structure. The 
anatomical evidence supports the view that there is a 
real, though it may be a collateral, relationship 
between the two groups. 
DUBLIN. 
Royal Irish Academy, April 22.—Rev. Dr. Mahaffy, 
president, in the chair.—The following papers were 
read:—M. J. Conran: The Riemann integral and 
measurable sets. In this paper a method is given 
of extending the notion of integration to measurable 
sets without making use of any theory of generalised 
integration. Following the 
NO. 2219, VOL. 89] 
| of a fairly general character obtained. 
treatment of the theory of content, the integral is 
first defined for a single interval, then for a set of 
open intervals, then for a closed set, &c. In apply- 
ing the method to double integrals, it has been found 
necessary to examine the conditions under which the 
double and repeated Riemann integrals are equal 
when the region of integration has a frontier of posi- 
tive content. This has been done, and some results 
W. West: 
Fresh-water algz (in connection with Clare Island 
Survey). About 1100 species, varieties, and forms are 
enumerated, some with many localities, others being 
local. The research has proved that the district, 
lying on the older Paleozoic rocks, is a very rich 
one for this class of plants, and has resulted in the 
addition of a number of species, varieties, and forms 
new to science, as well as adding many others to 
the already known rich Irish algological flora. This 
is one of the most comprehensive reports of the 
investigation.—G. P, Farran: Decapoda (Clare Island 
Survey). The Decapoda of the Clare Island district 
include most of those recorded from the west coast 
of Ireland, with the exception of the burrowing 
forms. The majority of the species represented 
range. from the Mediterranean to Norway, those 
having a distinctly northern distribution being very 
few.—W. M. Tattersall: Schizopoda and Cumacea 
(Clare Island Survey). Thirty-five species belonging 
to these groups of crustacea are enumerated from 
the Clare Island marine area. None are new to 
science, but one Mysid is new to the fauna of Ireland 
and eight Mysidz to the area under consideration.— 
N. H. Foster: Land and fresh-water Isopoda (Clare 
Island). The terrestrial isopod fauna of Clare 
Island is similar to that of the adjoining mainland. 
Nine species were observed on the island, and of 
these eight have likewise been taken on the West 
Mayo mainland. Detailed notes are given respect- 
ing these species, and it is noted that many specimens 
of Oniscus asellus and Porcellio scaber are of larger 
size and brighter coloration than usually obtains in 
Ireland. Asellus aquaticus was the only fresh-water 
species found on the island.—R. Southern: Platy- 
helmia (Clare Island Survey). This paper dealt 
chiefly with the free-living Turbellaria of the. dis- 
trict. _ Fifty species were found, five of which live in 
fresh water and forty-five in the littoral and shallow 
waters of Clew Bay and Blacksod Bay. Five of 
these had not previously been recorded from the 
British Isles, and twenty-nine were additions to the 
Irish fauna. 
Paris, 
Academy of Sciences, April 29.—M. Lippmann in the 
chair.—M. Bassot: The compensation of the new 
meridian of Quito. Remarks on the memoirs of the 
geodesy expedition to the equator, dealing with the 
observations obtained in the measurement of the arc 
of the meridian of Quito and the reduction of these 
observations.—Maurice Hamy: The temperature regu- 
lator in use with the stellar spectrograph of the Paris 
Observatory. The expansion of creosote, contained in 
a long serpentine tube, actuates through a mercury 
column an electrical relay. The instrument is 
capable of controlling the temperature to about o’o1° 
C.—A. Chauveau: The réle of the preponderating 
retinal impression in stereoscopic inversions.—MM 
Carimey, Raveau, and Stablo: Observation of a shadow 
on the sky after the central phase of the eclipse of 
April 17.—A. de La Baume-Pluvinel: The observation 
of the solar eclipse of April 17. A kinematograph 
was arranged to photograph the sun and a chrono- 
meter simultaneously, with a velocity of thirteen, to 
fourteen images per second. The times were checked 
analogy of Young’s } by wireless signals from the Eiffel Tower.—R. Jouast 
