scholarly journals III. On the leaves of calamites (calamocladus section)

The last few decades have seen enormous additions to our knowledge of the structure of fossil plants, and we have now a very complete acquaintance with the stems, roots, and fructifications of a considerable number of Coal Measure genera. But although this is the case, comparatively little is yet known about the structure of their foliarorgans. Renault's classic researches brought to light many interesting leaves, particularly from the Autum district; but scarcely any petrified leaves from the English deposits have been studied in detail. This no doubt, constitutes a very serious gap in our knowledge of the Palæozoie flora, and it is my intention to endeavour to make detailed studies of leaf structure in the principal groups of Coal Measure plants. The subject has important bearings in several directions, apart from a merely descriptive interest. It is now generally recognised that the leaves of plants growing in different habitats almost universally exhibit adaptations correlated with the physical conditions of their surroundings, and definite types of structure are developed according to the amount of water and light supplied. A considerable mass of evidence on this subject is being accumulated by the study of modern plants. It seems perfectly legitimate to use this evidence in the reverse manner, and from the characters of leaf structure to draw deductions as to the climate and conditions of growth in Coal Measure times. Leaves show these modifications more strikingly than any other parts of the plant, and hence a detailed know­ ledge of fossil leaves is of great importance in the discussion of the climatology of the Coal Measure period, and incidentally in regard to the question of the formation of coal.

In spite of the great progress which has been made in the study of Coal Measure plants, the subject of leaf structure has been largely neglected. The author is investigating the structure of the leaves of the principal groups of palæozoic plants with the view of determining their morphological and biological characters, and also of obtaining some knowledge of the conditions under which they grew. The speimens of Calamite leaves described in this paper have been found chiefly in slides in existing collections, and most of the material originally came from the Halifax Hard Bed of the Lower Coal measures.


Author(s):  
Orhun Soydan

Family health centers in Turkey started to be implemented for the first time in Düzce in 2004 years within the scope of Law No. 5258. While determining the physical conditions of the places where family health centers are built, the first item in the regulation is that the building should be easily accessible. This situation shows the importance of the subject in terms of accessibility. While determining the features of the places where FHCs will be made, environmental characteristics are also taken into consideration. Environmental features are effective in determining the FHCs location in different ways. These impacts are divided into two groups: the physical features that pavements, roads and parks can include, and the social, cultural and institutional features of neighborhoods that include local social ties and collective activities. From this point of view, the importance of the location of family health centers relative to roads and houses is understood. The aim of this study is to examine the accessibility of Family Health Centers in Konyaaltı, Antalya, on a neighborhood basis using Geographic Information Systems. Konyaaltı has 21 Family Health Centers. As a result of the analyses, it was determined that most of the neighborhoods had problems in terms of accessibility, while a very few of them did not experience problems in terms of accessibility. In terms of the total number of buildings, the ratio of buildings that are 500 meters walking distance from any family health center by using highways is 35.56%. With these rates, 3,634 of the 10,2018 buildings remain within the limits of the regulation. Finally; suggestions were made to increase accessibility to these areas.


Dialogue ◽  
1999 ◽  
Vol 38 (3) ◽  
pp. 561-566
Author(s):  
Irene Sonia Switankowsky

Many theorists in epistemology and mind accept externalism with respect to content–namely, the claim that the conditions that individuate mental content are external to the occurrence of that content as a mental fact. Whatever it is that distinguishes a pain in the knee from a pain in the toe—or, alternatively, whatever it is that makes it possible for the subject to discriminate this pain as a pain in the knee from that pain as a pain in the toe—are factors and conditions located in the physical and external world. This much externalism seems to be required even if one is a thoroughly entrenched mentalist. This “content externalism” is captured, fairly effectively, by the more traditional distinction between concepts and percepts. What is then asserted by the mentalist is that concepts have their source or origin in the external world, but the perceptual content does not. Perceptual content can be identified in different ways which are: (1) the view that identifies the distinguishing feature of the perceptual with qualia, a position not far removed from the Lockean distinction between Primary and Secondary qualities; or, (2) the perceptual might also be characterized in terms of representationalism, where qualia are an essential part of the representational medium, but where the representational medium contains conceptual content as well. In either case, the perceptual is Type and/or Token distinct from whatever is the external physical conditions or states of affairs causally responsible for the occurrence of either the conceptual content or the perceptual content. An argument for the claim that percepts (colours, sounds, smells, touches, and so on) are essential and necessary is that, without such percepts, there can be no experience.


The fossils which form the subject of the present paper are Cryptogamic strobili showing evident Lycopodiaceous affinities, but differing in important points from other fructifications of that family, so that it appears necessary to establish a new genus for their reception. The specimens are derived from the Coal-measures of Lancashire and Yorkshire, and are calcified, the internal structure being thus preserved in considerable perfection. As our present knowledge of the forms in question is entirely due to the researches of the late Professor W. C. Williamson, it will be necessary to give a short historical summary of the results which he attained, before going on to my own observations.


1895 ◽  
Vol 37 (2) ◽  
pp. 307-359 ◽  
Author(s):  
Robert Kidston

The tract of land embraced in the area from which the fossils have been derived, that form the subject of the present Memoir, extends in an easterly direction from Saltcoats to Newmilns, a distance of about 19 miles. At both extremities, the Coal Measures narrow down to under half a mile wide at Saltcoats, and about a mile broad at Newmilns. The greatest width is found towards the centre of the field, where in a northeast and south-west direction it is over 12 miles broad.


1871 ◽  
Vol 161 ◽  
pp. 477-510 ◽  

A few preliminary words may he necessary to prevent misunderstanding respecting the claims and objects of the following memoir. When I entered upon the investigation of which it records the results, I found, in the writings of various British and foreign authors, a copious Calamitean literature; hut the widest discrepancies prevailed amongst them both as to facts and to inductions. I therefore determined to pursue the study of this group of fossils as if de novo, to record the facts which I observed, and to draw from those facts alone such inferences as seemed legitimate, both facts and inferences being in a certain sense, and so far as was possible under the circumstances, new and original. But it necessarily follows that some of these facts and inferences are not absolutely new, though many of them, I think, will he found to he additions to our knowledge of the subject; whilst others, though not new, have presented themselves to me in a light different to that in which they have been regarded by my able predecessors in the study. Such being the object of the memoir, I have not deemed it desirable to include in it a record of all the observations made by preceding writers. As a rule I have only referred to them when the discussion of some moot point rendered such a reference necessary. The fundamental aim of the memoir is to demonstrate the unity of type existing amongst the British Calamites. Brongniart, Dawson, and other writers believe that there exist amongst these plants two types of structure, the one Cryptogamic and Equisetaceous, the other Exogenous and Gymnospermous; on the other hand, Schimper and Carruthers regard the whole as Equiseceous, affording an example of the diversity of opinion on fundamental points to which I have already referred. Of course, before arriving at their conclusions, Brongniart, and those who adopt his views, had fully apprehended the exogenous structure of the woody zone of the Calamite, which is further illustrated in this memoir. The separation of each internode into vertical radiating plates of vascular and cellular tissues, arranged alternately, was familiar to Brongniart, Unger, and other early observers. Cotta regarded the cellular tracts (my primary medullary rays) as medullary rays ; but this interpretation was rejected by Unger, and the same divergence of view on this point has recurred amongst subsequent writers. Unger also noticed what I have designated secondary medullary rays, but at a much more recent date Mr. Carruthers disputed their existence. In their 'Fossil Flora of Great Britain,' Lindley and Hutton gave very correct illustrations of the position of the roots of Calamites relatively to the stem ; and yet for years afterwards some of their figures reappeared in geological text-books in an inverted position, the roots doing duty as leaves ; so far was even this elementary point from being settled. The true nature of the common sandstone form of Calamites, viz. that they are inorganic casts of the interior of the woody cylinder from which the pith has been removed, has been alike recognized by Germar, Corda, and Dawes; but they referred the disappearance of the cellular tissues of the pith to inorganic decay which took place subsequently to the death of the plant. It appears to me that the condition in which we find these cellular tissues affords no countenance to this conclusion. They are as perfectly preserved, when present, as any of the other tissues of the plant. Their inner surface, nearest the fistular cavity, presents no appearance of death and decay, but of rupture and absorption, which I conclude has occurred during life,—a different hypothesis from that adopted by my predecessors, and for which my reasons will be assigned in the memoir. The labours of Mr. Binney are referred to in the text. He figured the longitudinal internodal canals, but was disposed to believe that they had merely formed passages for vessels. He gave, however, excellent figures of the woody wedges, the primary medullary rays, and the cellular medulla, with its nodal septa or diaphragms .


Hasta Wiyata ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 16-24
Author(s):  
Maulidia Tifani Alfin Nur Hardiana ◽  

This study aims to 1) analyze the value of culture; and 2) analyze linguistic elements in praise of "Sembahyang". The method used in this research is the literature and literature hermeneutic method. The object of this study is a compliment entitled "Sembahyang" which is analyzed based on cultural values and linguistic elements. Based on the analysis, it can be concluded that the cultural values to be conveyed in this praise that all people have the same position in the eyes of God. God will not look at the economic conditions, classes, social strata, and physical conditions of his people. Therefore, as a people of creation God basically has the same obligation towards God. The linguistic element in the praise lyrics uses a lot of inversion sentences, namely the existence of a predicate precedes the subject.


1898 ◽  
Vol 62 (379-387) ◽  
pp. 166-168 ◽  

The fossils which form the subject of the present paper are Cryptogamic strobili, showing evident Lycopodiaceous affinities, but differing in important points from other fructifications of that family, so that it appears necessary to establish a new genus for their reception. Two species are described, one of which ( Spencerites insignis ) is already known to us from the investigations of Williamson, who named it first Lepidostrobus insignis , and afterwards Lepidodendron Spenceri while the other ( Spencerites majusculus ) is new.


1872 ◽  
Vol 162 ◽  
pp. 283-318 ◽  

In the last memoir which I laid before the Royal Society I described a number of forms of Lepidodendroid plants from the Coal-measures, without making any material attempt to ascertain the relationship which they bore to each other. I now propose to carry the subject somewhat further, and to show that some of these apparently varied forms of Lycopodiaceæ merely represent identical or closely allied plants in different stages of their growth. The discovery of some remarkable beds in Burntisland, by George Grieve, Esq., and his persistent kindness in supplying me abundantly with the raw material upon which I could work, have enabled me to do this in a manner, at least, satisfactory to myself. Upon the geology of these remarkable beds I will not now enter, beyond saying that they appear to have been patches of peat belonging to the lower Burdiehouse series, which are now imbedded in masses of volcanic amygdaloid. The stratum, where unaltered by contact with the lava, is little more than a mass of vegetable fragments, the minute structure of most of which is exquisitely preserved. The more perfect remains that are capable of being identified belong to but few types. The most abundant of these are the young twigs of a Lepidodendron , portions of the stem of a Diploxylon , stems of a remarkable Lycopodiaceous plant belonging to my new genus Dictyoxylon (but which, for reasons to be stated in a future memoir, I propose to unite with Corda’s genus Heterangium , under the name of H. Grievii ), and fragments of Stigmaria-ficoides . Along with these occur, but more rarely, several other curious Lycopodiaceous and Fern stems, and those of an articulated plant, which I believe to be an Asterophyllites ; also some true Lepidostrobous fruits and myriads of caudate macrospores belonging to the Lepidostrobi . The first point to be noted is that all the Lepidodendroid branches are young twigs. No one example of a large stem has been found presenting exactly the same structure as these small branches, which, as already stated, are so abundant. On the other hand, all the Diploxylons are large branches or matured stems. These facts at once suggested the inquiry whether the two plants referred to might not be complementary to each other. A careful and very extended study of a large number of specimens has convinced me that such is the case. I have made more than a hundred sections of the two forms, and the result has been a remarkably clear testimony that the Lepidodendra are the twigs and young branches of the Diploxylon -stems. I am also led to the conclusion that the Lepidostrbi , with their peculiar macrospores and microspores, belong to the same plant. I will examine each of these forms in detail.


1890 ◽  
Vol 35 (2) ◽  
pp. 391-417 ◽  
Author(s):  
Robert Kidston

A copy of Mr Marrat's paper “On the Fossil Ferns in the Ravenhead Collection” having come into my hands, I was led to visit the Liverpool Free Public Museum in 1886, and again in 1887, with the object of examining this interesting collection, and while doing so I received every assistance from Mr Thomas J. Moore, the Curator, and Mr F. P. Marrat, to whom I take this opportunity of expressing my indebtedness for the many kindnesses I received while studying the Ravenhead plants. I have further the pleasure of acknowledging the privilege accorded me by the Museum Committee, through the kind offices of the Rev. H. H. Higgins, which allowed me to have a number of specimens sent to Stirling, where I could more advantageously examine them than in the Museum, where the literature of the subject is limited.


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