NATURE 
[JANUARY 7, 1904 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, November 19, 1903.—‘‘On the Nemato- 
cysts of Afolids.”” By G. H. Grosvenor, New College, 
Oxford. Communicated by Prof. W. F. R. Weldon, F.R.S. 
The nematocysts of zolids were discovered by Alder and 
Hancock in 1843. As early as 1858 Strethill Wright com- 
municated to the Royal Phys. Soc. of Edinburgh the 
results of some observations which seemed to prove that 
these nematocysts were not developed in the body of the 
zolid, but derived from its ccelenterate prey. This paper, 
though republished in the Microscopical Journal four years 
later, seems to have been entirely overlooked, and the 
nematocysts of nudibranchs have been generally supposed 
to be developed in situ, and have often been quoted as an 
inexplicable example of homoplasy or even as evidence of 
a close relationship between Mollusca and ccelenterates. 
C. O. Glaser has, however, recently supported the opposite 
view. 
The evidence brought forward in the present paper in 
support of Strethill Wright’s view is as follows :— 
(1) Not only are the nematocysts of eolids and 
Ceelenterata identical in plan and in mode of discharge, but 
each of several distinct types occurs in both groups. 
(2) The nematocysts of zolids vary from individual to 
individual within the species, and even in the same in- 
dividual there may be nematocysts characteristic of two or 
more distinct genera or families of ccelenterates. 
(3) Whenever it is known on what ccelenterate an zolid 
has recently fed, the nematocysts of the two are found to 
be identical. Also the nematocysts in the faeces are always 
indistingu-shable from one of the kinds, at least, in the 
cnidosac. 
(4) Those zolids (Janide, Fiona, and Calma glaucoides) 
which are known to feed on non-ccelenterate prey have no 
nematocysts. 
(5) Nematocysts and other indigestible bodies have been 
observed to pass through the ciliated canal from the cavity 
of the gastric gland into the cnidosac. 
(6) Strethill Wright’s most conclusive evidence was derived 
from an experiment of feeding an zolid on a hydroid with 
nematocysts different from those in the cnidosacs of the 
eolid. This experiment has been repeated several times, 
always with the result that the new nematocysts very soon 
appeared in the cnidosacs of the zolid. In one case three 
specimens of Rizzolia peregrina, with only small pip-shaped 
nematocysts (6-5 «) in their cnidosacs, were fed on Pennaria 
Cavolini, a hydroid with very distinct ovoid nematocysts of 
two sizes (25 w and 7 uw). After about a month of this diet 
the pip-shaped nematocysts were almost entirely replaced 
by those of Pennaria. These latter were enclosed in cnido- 
cysts in the ordinary way. 
Though the nematocysts of zolids are derived from their 
food, they discharge the threads on extrusion from the 
cerata into sea-water, and there can be little doubt that 
they are used as weapons of defence. But an important, and 
probably the original function of the terminal openings of 
the cerata is the elimination of the indigestible nemato- 
cysts, which, on account of the diffuse character of the 
digestive s~stem, cannot easily be got rid of through the 
anus onl 
The face of their discharge when extruded naked into 
the sea-water from the cnidosacs of an zolid proves that 
nematocysts work without the intervention of living proto- 
plasm. <A study of the conditions of discharge of nemato- 
cysts in cocelenterates and zeolids, and of their behaviour 
in various solutions, leads to the conclusion that we have 
to do with a phenomenon of osmosis. 
In the development of the cnidocysts two kinds of cells 
take part; one, the so-called ‘‘ cnidoblast,’? ingests and 
arranges the nematocysts, while others lying between 
adjacent cnidocysts take part in the secretion of the mem- 
branous walls. Both kinds degenerate in the fully formed 
cnidocyst. 
December 13, 1903.—‘‘ Preliminary Note on the Resist- 
ance to Heat of B. anthracis.’’ By A. Matlock, F.R.S., 
and Lieut.-Colonel A. M. Davies. 
This paper describes a series of experiments made by 
heating water infected with anthrax to various tempera- 
NO. 1784, VOL. 69] 
tures for various times, in order to determine the tempera- 
ture and time necessary for the destruction of the spores. 
The infected water was sealed in glass tubes and heated 
in steam in an apparatus which was designed so that any 
desired temperature could be maintained and simultaneously 
recorded. 
The highest temperature employed was 120° C. and the 
lowest 99°. 
The longest time for which the temperature was main- 
tained was twenty minutes, and the shortest twenty 
seconds. 
From statements made by good authorities as to the 
great heat resisting power of the spores of anthrax, it was 
expected that the temperature required to destroy the spores, 
when expressed as a function of the time for which the 
temperature had to be maintained, would form a curve, the 
temperature decreasing as the time of its application in- 
creased, 
The authors, however, found that out of 95 experiments 
in which the tubes were heated to 100° C. or more, in 81 
all life was destroyed, and out of*the remaining 14 experi- 
ments, in which some growth took place after cultivation 
in broth, 12 had become contaminated. After heating 18 _ 
experiments were made at temperatures,between 99° C. and 
roo? C. In 5 of these experiments some growth occurred 
after cultivation, 4 of these being found contaminated. 
The conclusion arrived at is that when anthrax spores 
are heated in water to 100° C. or more, even for twenty or 
thirty seconds, their destruction is almost certain. 
Chemical Society, December 16, 1903.—Prof. W. A. 
Tilden, F.R.S., president, in the chair.—The following 
papers were read :—The relative strengths of the alkaline 
hydroxides and of ammonia as measured by their action 
on cotarnine, by Messrs. Dobbie, Lauder and Tinkler. 
When aqueous solutions of cotarnine are treated with 
alkaline hydroxides or ammonia the alkaloid is changed 
from the ‘‘ ammonium hydroxide ’’ form to the ‘* carbinol ’” 
form. As solutions of these two forms of cotarnine exhibit 
very different absorption spectra, it is possible by this means 
to observe the rates at which this change is brought about 
by different allsalis. The relative strengths of the alkaline 
hydroxides as determined by this method are practically 
identical with those obtained by other physical methods. 
—Peroxylaminesulphonates and hydroxylaminetrisulphon- 
ates, by Mr. T. WHaga.—An investigation of the 
sulphazilates and metasulphazilates first obtained by Fremy. 
Peroxylaminesulphonic acid, by Dr. E. Divers. The 
author shows that the bluish-violet substance produced by 
the action of sulphur dioxide on sulphuric acid containing 
nitrososulphuric acid is probably, as has already been 
asserted by Sabatier, peroxylaminesulphonic acid, 
—Constitution of nitric peroxide, by Dr. E. Divers. 
shown from the results of Haga’s investigations that the 
mono-nitric peroxide must have the formula O: N.O, whilst 
the dinitric peroxide must have the constitution (NO),O,. 
—Halogen derivatives of diphenyl and dihydroxydiphenyl, 
by Mr. J. C. Caim.—Notes on some natural colouring 
matters, by Messrs. A. G. Perkin and E. Phipps. The 
flowers of Prunus spinosa contain the two colouring matters 
quercetin and  kampherol. The Japanese  dye-stuff 
““Fukugi’’ contains a yellow substance closely related to 
luteolin. A number of derivatives of morin, hesperitin, 
myricetin and curcumin are also described.—The estim- 
ation of methyl alcohol in the presence of ethyl alcohol, by 
Messrs. T. E. Thorpe and J. Holmes. The method is 
based upon the difference in behaviour of these two alcohols 
towards a mixture of potassium dichromate and sulphuric 
acid.—Separation and estimation of silver cyanide and silver 
chloride, by Mr. R. H. A. Plimmer. The mixture is 
treated with boiling dilute nitric acid, and the hydrocyanie 
acid so liberated distilled off and estimated as silver cyanide. 
—Estimation of hydroxyl radicles, by Messrs. H. Hibbert 
and J. J. Sudborough. A modification of Tschugaeff’s 
method is described.—Diortho-substituted benzoic acids, 
part v., formation of salts from diortho-substituted benzoic 
acids and organic bases, by Messrs. J. J. Sudborough and 
W. Roberts.—Cis-7-camphanates of d- and /-hydrindamines, 
by Prof. F. S. Kipping.—Resolution of dl-methylhydrind- 
amine, by Mr. G. Tattersall.—Isomeric salts of d- and 
the 
potassium salt of which is described in the preceding paper. 
It is_ 
