¥8 NATURE 

manner as the contents of the paper just read have shown.—The 
next communication was a note by Mr. Chapman “On the 
Oxides of Nitrogen.” In a paper read at the last meeting of 
the Chemical Society, Mr. Chapman mentioned that he had 
quantitatively estimated nitric oxide by converting it into nitric 
acid, and determining the latter by the production and weighing 
of the baryta salt. Objections were then raised as to the possi- 
bility of the completeness of such a conversion. Mr, Chapman 
now endeavoured to show by referring to well-known chemical 
facts that whether N, O,, N, O,, or N, Og be formed when N O 
is left with excess of oxygen over water, the final result must be 
the transformation into nitric acid. Mr. Harcourt reasserted 
that on his passing nitric oxide into oxygen he obtained as result 
nitric peroxide ; when reversing this order and passing oxygen 
into nitric oxide, a mixture of N,O,and N,O, seems to be 
formed. Mr. Chapman replied that the different results obtained 
by Mr. Harcourt and by himself were in all probability due to 
differences of the temperatures at which the respective experi- 
ments had been executed. Prof. Williamson took occasion of 
this repeated mentioning of nitric peroxide to remark that this 
= 
compound may be viewed as ane O, 7.2, as water in which 
the one hydrogen was replaced by N O, the other by N O.. 
Linnean Society, November 17.—Dr. J. D. Hooker, V.P., 
in the chair. Notes on the Passifloree, by Dr. M. T. Masters. 
The paper treated of the morphology of the whole order, in- 
cluding the organography of all the genera ; the minute anatomy, 
development, mode of fertilisation, and the movements which 
take place in the stamens and pistils of Passifora ; the affinities 
of the order, together with an inquiry into the value of charac- 
ters, and the mode of estimating them ; a complete list of the 
genera and species, with detailed descriptions of all the species 
which are not either American or African, and which will be 
published elsewhere ; and, lastly, an account of the geographical 
distribution. (1.) Organography.—The tendrils, as shown by 
their development, minute anatomy and position, and the fact 
that they occasionally bear flowers, are merely modified flower- 
stalks. The leaf, whether single or divided, always commences 
in development at the apex, and proceeds from above downwards. 
There are only three bracts instead of five, as there would be 
in a perfectly symmetrical arrangement ; their position, as well 
as that of the other parts of the flower, relative to the axis has 
been somewhat incorrectly described by Payer, Griffith, and 
Schleiden. Jussieu and St. Hilaire held that there is no true 
corolla in the passion-flowers, but two calycine whorls, because 
both organs fall at the same time. But the mode of develop- 
ment and the internal structure clearly demonstrate that the 
inner whorl is a true corolla ; the calyx is quincuncial, while the 
petals appear simultaneously. The flower-tube is, according to 
Bentham, composed of a union of the calyx and corolla; Dr, 
Masters, on the other hand, believes it to be an expansion of the 
axis. Its development is comparatively late. The form of the 
corona was traced from its simplest form in Zyrnera to its most 
complicated arrangement in some Modeccas and Passifloras, in 
all cases it is a mere projection from the flower-tube, and is of 
late development, and morphologically of little importance, 
though essential to the individual life of the plant. The inner 
portion of the tube is a glandular secreting surface. Each sepa- 
rate thread of the corona has its own distinct vascular bundle. 
The stamens, unlike those of Cucurbitacee, are not perigynous, 
but truly hypogynous. The gynophore becomes gradually de- 
veloped, raising the stamens with it. The anthers are inva- 
riably two-celled. The pistil is singularly uniform, one-celled, 
made up of three united carpels, with three parietal placenta 
and three stigmas. (2.) Mode of Fertilisation.—The arrange- 
ment of the sexual organs favours cross-fertilisation. The 
anthers, originally introrse, become, when fully developed, 
distinctly extrorse, and it is thus rendered difficult for the pollen 
to fall on the stigmas of the same flower ; it falls on to the rays 
of the corona, on which insects alight in search of the honey 
concealed at the base of the tube, and carry the pollen away 
to other flowers. Some species are more easily fertilise by 
pollen belonging to a different species than by their own ; hence 
hybridisation abounds. (3.) Affinities—Dr. Masters connects 
the Lassifloree rather with the Zurneracee, Samydacee, Violacee, 
and Sauvagesiee than with the Cucurbitacee, chiefly on account 
of their truly hypogynous stamens. (4.) Geographical Distri- 
bution. —The order is essentially tropical, occurring between 
30° N. and 30° S. latitude. Taking the genus Passiflora as the 
type, it is almost exclusively American, and chiefly Brazilian ; 

[Mov. 24, 1870 

a few outliers of the true passion-flowers occur in Madagascar 
and Mauritius, the latter probably introduced, and in North 
America there is a very remarkable form, the P. incarnata, or 
original passion-flower of the Jesuits ; it is an annual, and appa- 
rently an alien, but remarkably uniform and invariable ; its repre- 
sentative in Brazil is P. edu/is, a shrub, and an extremely variable 
plant. On the western side of the Andes you get entirely different 
forms, especially the Zacsonias, which have generally a much 
longer flower-tube. In India there are a few species, not be- 
longing to the American section of the order, but to the Poly- 
anthea, which are found also in Ceylon and the Indian Archi- 
pelago, and one outlying species in an island aear Hong 
Kong. In Australia and the Pacific Islands occurs another 
perfectly distinct group ; in New Zealand a perfectly distinct 
form is met with; and, again, another in Africa, where no 
true passion-flower is indigenous, except the one in Madagascar ; 
the species here, few in number, belonging to six or eight distinct 
genera, —‘‘On the White-beaked Bottle-nosed Whale,” by Dr. 
Jas. Murie. The paper gave an account of several anatomical 
points in the structure of this whale, which had not been clearly 
described before. The little bag or sac connectéd with the double 
articulation between the lower jaw and the rest of the skull, which 
is found in all Mammals except the Cetacea, is however, present 
in the foetus of the latter. 
Mathematical Society, Noy. 10.—Prof. Cayley, President, 
in the chair. The following gentlemen were elected to form the 
council for the Session 1870-1:—President, W. Spottiswoode, 
F.R.S.; Vice-Presidents, Professors Cayley, Henrici, and H. J. 
S. Smith; Treasurer, Dr. Hirst; Hon. Secs,, M. Jenkins and 
R. Tucker; other Members, W. K. Clifford, T. Cotterrill, M. 
W. Crofton, *C. W. Merrifield, *J. F. Moulton, J. Stirling, 
Archibald Smith, Prof. Sylvester, J. J. Walker. Mr. J. 
J. Hamblin Smith, M.A., Caius College, Cambridge, was pro- 
posed for election. The new president having taken the chair, 
called on Prof. Cayley to read his paper, of which an abstract is 
given below—‘‘ Sketch of Recent Researches upon Quartic and 
Quintic Surfaces.” The classification of quartic surfaces is, even 
as to its highest divisions, incomplete ; and it is by no means eas 
to make it at once exhaustive and precise ; an examination of all 
the prima facie possible cases would include forms which do not 
really exist. Premising that the expression ‘‘singular” means 
double or cuspidal, or refers to a higher singularity; ‘*nodal”’ 
in general double (including the signification cuspidal), we may 
provisionally arrange the non-scrolar quartic surfaces as follows— 
I, without a nodal curve ; 2, with a nodal line ; 3, with a nodal 
conic; or line-pair; 4, with three nodal lines (not in the same 
plane) meeting in a point); 5, the quartic scrolls, omitting alto- 
gether the torse and cones. For the scrolls the division into 
twelve species appears to be complete (Memoirs by Cayley (3) (4), 
Cremona, and Schwarz). As regards non-scrolar surfaces, we 
have—1. Without a singular curve. The surface may be with- 
out a cnicnode (conical point), or it may have any number of 
cnicnodes up to 16 (Cayley, (5) ; Kummer (1) (2),). It may be re- 
marked that the wave-surface, or generally the surface obtained by 
the homographic deformation of the wave-surface, called by Cay- 
ley (1) (2) the ‘‘ tetrahedroid,” is a special form of surface with 16 
nodes. 2. Quartic surface with nodal Jine. Considered incident- 
ally in Clebsch (2) (3). 3- Quartic surfaces with nodal conic. 
Such a surface may be without cnicnodes, or it may have one, 
two, three, or four cnicnodes. The cases other than that of 
three cnicnodes are mentioned, Awmmer (1); but the ques- 
tion is examined and the remaining case of three cnicnodes 
established, Cay/ey (6). The general case of the nodal conic 
without cnicnodes is elaborately considered, Clebsch (1). See 
also Geiser ; the several cases of one, two, three, and four 
cnicnodes are considered, Aorndorfer. In the case where 
the nodal conic is the circle at infinity the surfaces have been 
termed ‘‘anallagmatic” (perhaps ‘‘bicircular” would be a 
more convenient name), and a great deal has been written 
on these surfaces by Moutard, Clifford, and others, The theory 
of the quartic surfaces with a cuspidal conic has been hardly 
at all considered, briefly referred to in Cayley (6), also in Cayley 
(8). ‘*I do not know that anything has beendone in regard to 
the quartic surfaces where the nodal conic becomes a line-pair, 
that is, where we have two intersecting nodal lines.” 4. Quartic 
surface with three nodal lines (not in the same plane) meeting in 
a point. This is in fact Steiner's quartic surface, and it has 
been the subject of numerous investigations. The author then 
* These gentlemen were not on the Council for the Session 1869-70. 
has 
