230 M. Marc Micheli on some Recent 
The specimens of limestone analyzed by Dr. Ehrenberg 
were brought from Gyzeh, on the left bank of the Nile, and 
from Mokattam, near Cairo, on the right bank. It was com- 
pact, the small Foraminifera serving as cementing-matter 
among the Nummulites of which the rock is mainly composed. 
The figured Foraminifera of plate xxiii. bear evidence, in 
the truthful engraving of their somewhat rough, partly ob- 
scured, and occasionally broken condition, to their having 
been closely cemented and much mineralized by carbonate of 
lime in their fossil matrix. 
[To be continued.] 
XXIV. — On some Recent Researches in Vegetable Physiology. 
By M. Marc Micheli. 
[Continued from p. 155, and concluded.] 
II. 
The study of the phenomena of which the interior of cells 
is exclusively the tlieatre, of the transformations which are 
manifested there, and of the substances which they contain 
has also produced some works which deserve notice, and in 
the first place the researches of M. Schroeder * upon the 
" spring period of the maple." The author has paid at- 
tention to all the successive phases presented by the develop- 
ment of the vegetation, from the ascent of the sap to the 
moment when the expanded leaves begin to decompose car- 
bonic acid. This is one of those complete and conscientious 
works which, even when they do not contain any very novel 
results, are nevertheless very useful to read and consult ; but 
it is difficult to give a clear notion of them in a few words. 
A glance at the course followed by M. Schroeder will show 
the great number of facts which group themselves within a 
framework such as he has adopted. 
The first part is entirely devoted to the study of the sap, 
its ascent, and its composition. The maple, under the lati- 
tude of Breslau, " loeeps " for about a month ; the sap rises 
gradually to a certain level, whence it descends again by de- 
grees, in proportion as the development advances. Holes 
pierced in the trunk at different heights enabled this sap 
to be collected daily ; and very numerous analyses keep us 
informed of the smallest variations in its composition. It 
always contains sugar, a transitory product of the transforma- 
tion of the starch accumulated in the tissues during the pre- 
* " Friihjalirsperiode des Ahoms," Pringsheim's Jahrb. vii, p. 261. 
Researches in Vegetable Physiology. 231 
ceding summer, and destined to become retransformed wlien it 
reaches the buds. The proportion, faithfullj represented by 
a great number of curves, is but slight at the first awakening 
of vegetation ; it increases gradually up to a certain maximum, 
in proportion as the vital phenomena acquire more intensity ; 
and, finally, it diminishes when the young organs, approach- 
ing the term of their development, are on the verge of suf- 
ficing for themselves. These facts are therefore perfectly in 
accordance with such a theory of growth as has been esta- 
blished by the researches of modern observers. 
The albumen and the mineral salts are successively studied 
from the same point of view ; and their dissemination in the 
sap at different heights at the same moment, and at different 
periods, is exactly governed by the different phases of deve- 
lopment. 
The second part is devoted to the microscopic examination 
of the bud. The different substances which are called upon 
to assist in the development of the young leaf are traced by 
means of reagents from cell to cell. Two, especially, give 
origin to detailed observations, namely starch and tannin. 
The dissemination of the former in the different tissues, its 
transportation through the starchy layers of the fibro-vascular 
bundles, its disappearance towards the point of vegetation, at 
the surface of which it speedily reappears as cellulose — all 
these different phases are taken up step by step ; and here, 
again, we find a confirmation of all that theory led us to 
foresee. 
As to tannin, it is developed in all the cells of the bud ; 
and when once it has made its appearance, it persists there 
without appreciable change. Its function has greatly embar- 
rassed M. Schroeder, as he was unable to recognize in it any 
of the characters of an excrementitial product, properly so 
called. The fact that it is constantly to be found in the 
youngest tissues (in which life is most intense) seems to indicate 
that it is a sort of final product, charged with a still unknown 
office in the life of the cell. If the true chemical nature of 
this substance were better known, the solution of the problem 
would perhaps become easier. 
Certain authors have thought that the course of vegetation 
in the Agaiics induced a marked exhalation of gaseous ammonia 
at their surface. M. Sachs mentions the fact in his ' Treatise 
on Physiology,' but without absolutely affirming it. M. Bor- 
scow * has undertaken a series of experiments, upon which he 
* Melanges Biologiquea tir& du Bull, de I'Acad. Imp. des Sci. de St.- 
P^tersb. tome vii. p. \'2\. 
232 M. Marc Micheli on some Recent 
relies to affirm positively the existence of this phenomenon. 
According to him, the production of gaseous ammonia is a ge- 
neral fact in the family of the Agarics ; the quantity of gas 
exhaled is in proportion to the vital activity of the plant, but 
has nothing to do with its weight. It is equally without any 
relation to the production of carbonic acid as a result of 
respiration. 
But quite recently MM. Wolff and Zimmermann* have ob- 
jected to these conclusions. In all their experiments they were 
only once able to recognize some traces of ammonia, and the 
Agaric was not under conditions so normal as the others. 
These two authors, therefore, believe that in the Agarics, as in 
other plants, ammonia is a product of the decomposition of 
the tissues, but a product which begins to make its appear- 
ance immediately the vital functions of the organism are 
slackened, 
Inuline, a substance of the starch-group, which is met with 
in a considerable number of plants, has been made by M. 
Prantl f the subject of a memoir crowned by the University of 
Munich. 
The results obtained by the author of this memoir are in all 
essential features in accordance with what MM. Nageli and 
Sachs have said of inuline. M. Prantl describes this substance 
as a hydrate of carbon, which differs from starch, cellulose, and 
lichenine in never taking on an organic form. Its fixity suffi- 
ciently differentiates it from dextrine. It seems to approach 
most nearly to cane-sugar. 
Inuline is constantly found in plants in the form of a solu- 
tion of 1 part of inuline to 7 of water. As in artificial solu- 
tions O'Ol gramme of inuline saturates 100 cub. centims. of 
water, we may suppose that when dissolving in the plant it 
undergoes transformation. It never apj)ears excejit in subter- 
ranean organs. 
This substance is pretty frequently produced in plants 
of different families, but especially in the Compositee. The 
dahlia and certain Helianthi contain considerable quantities 
of it. 
From a physiological point of view, inuline plays exactly 
the part of one of those nutritive principles which are put in 
reserve, such as starch, sugar, oils, &c. As we have just said, 
it exists exclusively in subterranean organs, tubers or rhi- 
zomes. At the moment of growth it is transformed into cane- 
sugar towards the collar of the root, then mounts into the 
* Bot. Zeitung, 1871, Nos. 18 and 19. 
1 Das Inulin, Munich, 1870 ; and Bot. Zeitung, 1870, No. 39. 
Researches in Vegetahle Physiology. 233 
stem in the form of starch, and thus passes towards the buds. 
Subsequently the starch produced in the leaves descends along 
the stem in the form of starch itself or of sugar; and it is only 
on its arrival in the root that it takes on the form of inuline. 
III. 
We cannot conclude this revision of the principal recent 
physiological publications witliout casting a glance upon a 
group of very interesting works, although these do not yet allow 
us to rise to general conclusions. We would speak of fecunda- 
tion in phanerogamous plants, and the part which insects per- 
form in it. The idea itself is not new ; and even a century 
ago Sprengel* cited numerous cases of flowers fecundated by 
the mediation of insects. But it is only in our time that it has 
been attempted to generalize these facts ; and Mr. Darwin was 
the first to put forwai'd the notion that the fecundation of a 
flower by itself is contrary to the laws of nature, and that the 
reproduction of a species is not well assured except by cross- 
ings between different individuals. 
A theory like this cannot of course be proved except by di- 
rect investigation of facts ,' and the facts, when we have to do 
with fecundation, are most minute, and demand peculiarly in- 
genious and patient observations. Several naturalists have 
advanced to the breach ; and we possess a fine collection of 
special memoirs, the conclusions from which already form a 
solid basis for theoretical ideas. However, if the observers 
have had to manifest great patience, the recompense waited for 
them at the end. Nothing is more curious than the details of 
organization by which spontaneous fecundation, apparently so 
easy, is rendered useless or even impossible. The researches 
of Mr. Darwin" himself upon the fecundation of the Orchids, 
upon the dimorphism of the primrose, and upon the trimorphism 
of Lythrum salicaria are well known. He has found imitators 
in MM. Hildebrandt and Delpino. Both these authors have 
published numerous memoirs, sometimes studying thoroughly 
all the details of fecundation in a certain plant or family, some- 
times tracing throughout the vegetable kingdom a certain type 
of fecundation, and pointing it out wherever it is manifested. 
M. Hildebrandt f, moreover, some time since, brought toge- 
ther all the data we possess upon the subject, and endeavoured 
to group them methodically. The perfectly uniform conclusion 
of all these works is, that in the great majority (if not in the 
totality) of plants direct and spontaneous fecundation is im- 
* Das entdeckte Geheimniss der Natur im Bau imd Befruchtung der 
Blunien. Berlin, 1793. 
t Die Geschlecliter-Vertlieilung bei den Pflanzen. Leipzig, 1867. 
234 M. Marc Micheli on some Recent 
possible, and that the intervention of insects is always ne- 
cessary. 
In a multitude of cases the expansion of the stigma does not 
take place at the same time as the opening of the stamens ; the 
flowers are what are called " dichogamous," and may be pro- 
tandric or protogynic. 
The former are most frequent. Entire and most important 
families enter this category, such as the LabiatfB, the Scrophu- 
lariacege, the Composite, and the Campanulacese. Here the 
office of insects is very evidently necessary; and it is facilitated 
by the most varied details of organization. For example, in 
the whole of the immense group Compositfe* the five stamens 
have the anthers soldered into a cylinder, which envelopes the 
pistil ; they open and allow the pollen to escape before the 
style has become elongated. The style bears, below the 
stigma, a certain number of rigid hairs, which retain the pollen- 
grains, and carry them forward with them in their ascending 
movement at the moment of the elongation of the style. The 
pollen thus carried up out of the cylinder of the anthers is col- 
lected by insects and transported to flowers the stigma of which 
is already expanded. 
In the Campanulaceasf, Lobeliaceaj, &c. the system is the 
same, only the appendages destined to retain the pollen on the 
style present a very variable form. 
In the whole of the group of Scrophulariaceous Labiatse % the 
axis of the flower is horizontal, and the stamens are approxi- 
mated beneath the upper lip of the corolla. The insects, in 
passing, separate and jostle them, cause the pollen to fall from 
them, and then transport it to a more advanced flower. In 
certain genera the stamens alone stand in the way of the insect, 
which always seeks the bottom of the flower, where the nectaries 
are. Later on they curve outwards, the style in its turn becomes 
elongated, and advances to take their place, and its recurved 
extremity caresses the body of the insect loaded with pollen. 
In certain plants in which the expansion of the reproductive 
organs is simultaneous, the part performed by insects is no less 
maintained. In their absence spontaneous fecundation, which 
nevertheless appears to be inevitable, does not take place, or 
produces very little effect. Such, for example, are numerous 
Leguminosse §, in which the stamens and the pistil are enclosed 
in the keel, in very close proximity. Insects, going to collect 
* " Ueber die Gesclileclitsverlialtiiisse bei den Compositen," Acta Leop. 
Carol. Tol. XXV. 1869, and Bot. Zeitung, 1870, No. 30. 
t "Ulteriori osservazioni suUa dicogamia nel regno vegetale," Atti 
della Soc. Ital. di Sci. Nat. vols. xi. & xii. ; and Bot. Zeitung, 1870, Nos. 
37-42. X Ihid. § Ibid. 
Researches in Vegetable Physiology. 235 
the nectar, touch the back of the keel ; the latter throws itself 
briskly backward ; the insect receives a few grains of pollen, 
and transports them to the neighbouring flower. Without 
this intervention, often not a single seed is produced. 
The family Fumariaceee, lately studied by M. Hildebrandt*, 
presents us with a perfectly analogous example. The stamens 
and the pistil are narrowly enclosed between the two petals, 
and appear to be removed from all exterior action. But the 
base of the petals, which is produced into a spur, offers an 
abundant provision of nectar. To reach it the insect must 
pass between the two petals, the upper part of which, borne 
upon a sort of hinge, separates easily. It thus loads itself 
with pollen. 
Lastly, some flowers are polymorphic. By this name we 
designate the species in which the stigma and the stamens, 
which are placed at different heights in the corolla, do not 
always occupy the same relative positions. In some individuals 
the stigma, borne upon a long pistil, passes the corolla more 
or less, whilst tlie stamens remain very short ; in others the 
stamens advance and the pistil remains short. 
Mr. Darwin t was the first to study this peculiarity in 
Primula and Lythrum. M. Hildebrandt has since observed a 
great number of polymorphic flowers. Better than any others 
they show the necessity of crossings. In fact a pistil is fer- 
tilized only by the stamens which are developed at the same 
height with itself relatively to the corolla, and consequently of 
necessity in another flower. Numbers in connexion with this 
subject are more eloquent than any thing else. In experiment- 
ing upon a trimorphic Oxalis, M. Hildebrandt J obtained the 
following results : — 
28 flowers with long styles, fecundated with pollen from 
flowers with long stamens, produced 28 capsules, each contain- 
ing on an average 11 '9 fertile seeds. 
23 flowers with long styles, fecundated with pollen from 
median stamens, produced 2 capsules, which, together, only 
furnished a single seed. 
14 flowers with long styles, fecundated with pollen from 
short stamens, produced no capsule at all. 
38 flowers with median styles, fecundated with pollen from 
median stamens, produced 38 capsules, containing on an ave- 
rage 11*3 seeds. 
* " Bestaubungsvorrichtungen bei den Fumariaceen,"' Pringsheim's 
Jalirb. vii. p. 423. 
t " Dimorphism in Primulu" Linn. Soc. Joum. vi. 1862. " H^t^ro- 
moi-pbisme et aes consequences," Ann. Sci. Nat. 1863, tome xix. 
X Bot. Zeitung, 1871, Nos, 26 and 27. 
236 Prof. Ehlers o?? the Development of Syngamus tracliealis. 
The other numbers correspond exactly with the preceding ; 
but these suffice to enable us to appreciate what takes place. 
It is likewise useless to prolong further the extracts from 
these works. What we have said is sufficient to show their 
general character, and the importance of the results already 
obtained. 
We here terminate this rapid and necessarily imperfect re- 
vision. But the quantity of materials is considerable, the 
subjects treated are very varied, and it is very difficult to 
bring the whole within the limits of a single essay. We hope 
on another occasion to be able to complete what is deficient here. 
XXV. — On the Development o/" Syngamus tracliealis. 
By Prof. Ehlers*. 
I AM indebted to the kindness of Baron von Freyburg, of 
Regensburg, for the opportunity of tracing experimentally the 
course of development of this worm, which is parasitic in the 
tracheae of birds, and, when it occurs in quantity in aviaries, 
pheasantries, and poultry -yards, produces considerable losses by 
the destruction especially of young and weakly animals. The 
parasite was introduced with some exotic birds into the aviary 
of the Baron von Freyberg during the illness of its owner, and 
has since occurred there more or less abundantly. The birds 
attacked by the worm betray this generally at first by a pecu- 
liar cough, during which they frequently throw the head to 
and fro, and not unfrequently at the same time expel small 
masses, which they generally pick up and swallow imme- 
diately. Large birds bear the parasitism of the worm, if it 
does not occur in too large numbers, for a long time ; small 
birds, on the contrary, often die suddenly — it would appear, 
especially by the pair of worms (which, as has long been 
known, reside in the trachea usually in coi^ula) placing them- 
selves in such a position that the passage of the air-tubes is 
stopped, and the birds are suffocated. 
In a Cardinalis virginianus which M. von Freyberg gave 
me for examination, and which, according to him, had long 
been infested by Syngamus^ I could see the animals in the 
entrance to the upper larynx, and take them out with a fine 
forceps. In freshly infected tits, the mucous membrane of 
the throat was more strongly reddened than usual, and exhi- 
bited some very fully charged superficial veins. But the most 
* From the * Sitzungsberichte der phys.-med. Societat zu Erlangen,' 
Dec. 5, 1871. Translated by W. S. Dallas, F.L.S., from a separate copy 
communicated by the Author.