Skip to main content

Full text of "On the Existence of Amorphous Starch in a New Tuberaceous Fungus"

See other formats


Ammonia was obtained either by treating aniline with nitrous acid, 
or by the action of nitrate of potash on the chloride, or by leading 
the binoxide of nitrogen into a solution of the nitrate; the latter 
was the way generally employed. After about twelve hours’ action 
of N0 3 on a solution of the nitrate in a water-bath, the solution 
was filtered from the nitrophenassic acid, and distilled with potash, 
the distillate treated with ether to dissolve out the aniline, redistilled 
in hydrochloric acid, evaporated, and the ammonia determined as 
platinum salt. These results have led me to try the action of 
nitrous acid on other organic bases, and I have already obtained from 
ethylaniline a base which to all appearance is ethylamin. The 
chloride gives off, when heated with potash, an alkaline inflammable 
gas, and the platinum salt resembles that of ethylamin; but the 
platinum determination made with it does not agree very well with 
that salt. I am now repeating the reaction on a larger scale, so that 
I shall shortly be able to see whether it is really ethylamin or not. 

The foregoing experiments were carried out in the Royal College 
of Chemistry under the direction of Professor Hofmann. 

III. “ On the Existence of Amorphous Starch in a new Tuber- 
aceous Fungus.” By Frederick Currey, Esq., M.A. 
Communicated by Joseph Dalton Hooker, M.D., F.R.S. 
Received December 17, 1857. 

Amorphous starch (including under that term all starch not in 
the form of the ordinary starch-granule) is rare in the vegetable 
world. Until the present year Schleiden was the only botanist by 
whom it had been noticed, and his observations have been doubted 
by Samo, Caspary, and Schenk. He (Schleiden) states (Grundzuge, i. 
181) that he has seen amorphous starch in the form of a thin pasty 
layer in the cells of thealbumenof Cardamomum minus , in Sarsaparilla, 
and in the rhizome of Carex arenaria . Sanio* has just published 
the result of some experiments made by him upon the cells of the 
epidermis of Gagea lutea. Upon applying a solution of iodine to 
these cells, he observed a fine flocculent blue precipitate in their in¬ 
terior. The blue colour was confined to the fluid contents of the 
* Bot. Zeitung, 19th June, 1857. 

The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to 

Proceedings of the Royal Society of London. 


cells, the primordial utricle and the nucleus becoming yellow under 
the iodine. 

Another observer, Dr. Schenk*, has lately noticed the occurrence 
of starch in a state of solution in the epidermal cells of the stem, 
leaves, and other parts of Ornithogalum nutans and Ornithogalum 
lanceolatum. These cells were found to contain (besides nuclei) a 
thick homogeneous fluid. Tincture of iodine coloured the fluid first 
wine-red, then violet, and finally indigo-blue ; and the fluid at the 
same time lost its homogeneous nature, and became finely granular 
and flocculent. 

The above mentioned are all cases of pheenogamic plants. The 
Fungi have hitherto been considered wholly devoid of starch, un¬ 
less, perhaps, the case mentioned by Schachtf may be an excep¬ 
tion. He states that he observed the mycelium of a small mould- 
fungus become clear blue under the action of iodine. He could not, 
however, ascertain whether the colour was in the membrane or in 
the contents, and if the former, it is as likely that the colour (being 
clear blue) arose from the presence of cellulose in a young condition, 
as from starchJ. 

Mohl, in his treatise on the vegetable cell, speaks of starch as 
probably existing in all plants except the Fungi, A special interest, 
therefore, attaches to any plant of the latter tribe, in which starch 
can be shown to exist, and such a plant has lately come under my 
observation. The fungus in question, which is interesting not only 

* Rot. Zeitung, July 17th, 1857. f Die Pflanzenzelle, p. 39. 

X In the ‘ Aimales des Sciences Naturelles/ 4th Series, vol. iii. p. 148, Nylan- 
der mentions a blue colour being produced by iodine in the summits of the asci 
of certain Sphcerice, which be attributes to the presence of lichenin. Gerhardt, 
however, in his ‘ Lehrbuch der Organischen Chemie, , states that a pure solution 
of lichenin is coloured yellowish by iodine. 

It is not easy to understand why the writers who speak of amorphous starch, 
take no notice of the lichens. Irrespective of the fact that the membrane of the 
asci of lichens is coloured blue by iodine, it is well known that the asci and para- 
physes are often surrounded by a viscid substance which is coloured by iodine in 
the same manner as starch, and which cannot well be anything else than starch 
in an amorphous state. Schacht, indeed, calls the viscid substance “ aufgequol- 
lene Starkebut this expression would be more applicable to the condition of 
starch when subjected to the action of hot water or sulphuric acid, and seems 
hardly consistent with his previous definition of the substance as a shapeless, 
paste-like mass. (See Die Pflanzenzelle, pp. 148, 149.) 


for its chemical composition, but as constituting a new genus in the 
family of the Tuberacei, occurred in the spring of the present year, 
growing gregariously upon fragments of wood on the sands by the 
sea-shore at Sketty, near Swansea. To the naked eye each indi¬ 
vidual specimen presents the appearance of a small, round, somewhat 
flattened body, of a dull yellow colour, and with an unevenness of 
surface caused by numberless convolutions of the coat of the fungus, 
which require the aid of a lens in order to be clearly seen. The 
diameter of the largest specimen does not much exceed the l-8th of 
an inch. Externally there is a strong resemblance to small speci¬ 
mens of Dacrymyces deliquescens , or perhaps a nearer still to the 
truffle described by Tulasne, in the cc Fungi hypogBei,” under the 
name of Hydnobolites cerebriformis. This resemblance, however, 
is only superficial, as will be seen by the following description of the 
plant when examined microscopically. The coat of the fungus con¬ 
sists of a convoluted membrane of considerable thickness, formed of 
several layers of cells, the outer of which are large and rounded, 
the inner long and flat. In most of the specimens the contents of 
the coat consist mainly of an innumerable multitude of naked spores; 
but in almost all, a careful examination will detect, here and there, 
isolated sacs or asci containing sporidia; and a few of the plants 
which were in a younger state than the rest exhibited asci in abun¬ 
dance, showing satisfactorily that the fungus must be classed with the 
Ascomycetes,—not with the Gasteromycetes. 

There is no doubt that the asci are absorbed at an early period, 
and the sporidia then form a dense mass. 

It is exceedingly difficult, from the crowded state of the contents, 
to trace out the manner in which the asci originate; but I have 
satisfied myself that they spring at intervals from threads proceed¬ 
ing from the inner surface of the thick external membrane. Fig. 4 
represents one of these threads with the asci springing from it, 
magnified 315 diameters. The asci themselves are broadly clavate, 
with a very short stem, and are frequently, if not usually, drawn out 
at the apex into a sort of point, as shown in figs. 2, 3 and 4. 

The sporidia are extremely curious. They are globular and co¬ 
lourless, and furnished with long delicate sharp rays projecting from 
the surface in every direction. Each sporidium is furnished with an 
internal nucleus, or probably oil-drop (sometimes broken up into 


several), which varies somewhat in size, and is sometimes in the 
centre of the'globe, sometimes placed eccentrically. Their form 
will he seen by reference to fig. 5. 

The average diameter of the sporidia is about -g-oVoth of an inch. 
Upon placing a thin section of one of the plants in water under the 
microscope, and adding a drop of solution of iodine, the sporidia in 
the course of a few seconds assume a more or less dark purple 
colour, precisely similar to that produced in starch by the same re¬ 
agent ; and not only are the sporidia themselves thus affected, but 
the fluid surrounding them is tinged of an intense purple colour for 
some distance round the mass of sporidia. This latter colouring is 
doubtless produced by the effect of the iodine upon a viscid matter 
which surrounds the sporidia, and which may either originate in the 
disintegration of the asci, or may be an independent secretion. 
There can be little doubt, I think, that this viscid matter is starch 
in a state of solution. It might be taken for dextrine, but that it 
differs from that substance in assuming a purple colour under iodine. 

The sporidia, although coloured by iodine in the same manner as 
starch-granules^, do not exhibit any cross when viewed by polarized 
light. The small size of the Fungi precludes the possibility of pro¬ 
curing a sufficient quantity of the viscid matter to test its effect upon 
the plane of polarization. 

I find the sporidia unaffected by boiling water or even by long 
soaking in sulphuric acid, in which respect they differ from starch- 
granules. The purple colour, however (as is the case with starch), 
disappears under the action of heat or of alcohol. 

I have named the plant Amylocarpus encephaloides , for reasons 
sufficiently obvious from the above description. Its systematic 
position is certainly with the Tuberacei, but it has no near allies. 
The only plant resembling it in structure is Endogone , but it is 
doubtful whether the vesicles of Endogone be spores or asci. If the 
latter, the affinity with Endogone would be close. 

In conclusion I may mention, that in a very late number of the 
‘Annales des Sciences Naturelles’ (4 serie, vol. vi. p. 318), which 
has reached me since my first observations on the above fungus, 
M. Tulasne remarks, that in several species of Erysiphe the tips of 

* The blue colour does not extend to the nucleus of the sporidia, which is yellow 
under the iodine. 


the radicular appendages are tinged blue by solution of iodine, and 
that he has observed the same effect produced upon the matter con¬ 
tained in the summits of the asci, and upon the mucous envelope of 
the sporidia of several species of Spkesria. It would seem, there¬ 
fore, that the absence of starch can no longer be considered as cha¬ 
racteristic of the Fungi, and that the existence of that substance in 
an amorphous state may be considered as satisfactorily proved. 


Fig. 1. Vertical section of the coat of the Fungus, showing the successive layers 
of cells, the innermost of which give off threads into the interior of the 
plant, X 315 diameters. 

Figs. 2 and 3. Asci with sporidia, X 415. In fig. 3 the sporidia are only partially 

Fig. 4. The extremity of a thread showing the mode of origin of the asci, X 315. 
Fig. 5. Free sporidia, X 415. 

IV. “ On the Singular Solutions of Differential Equations/” 
By the Bev. Robert Carmichael, Fellow of Trinity Col¬ 
lege, Dublin. Communicated by Arthur Cayley, Esq. 
Received December 28, 1857. 


The objects contemplated in this paper are the following:— 

1. The reduction to a symmetrical form of the well-known theo¬ 
rem by Clairaut for the integration of differential equations in a 


Fig. 1. Vertical section of the coat of the Fungus, showing the successive layers 
of cells, the innermost of which give off threads into the interior of the 
plant, x 315 diameters. 

Figs. 2 and 3. Asci with sporidia, x 415. In fig. 3 the sporidia are only partially 


Fig. 4. The extremity of a thread showing the mode of origin of the asci, X 315. 

Fig. 5. Free sporidia, x 415.