(After Haeckel.) Nerve ring.
- Trophosome polyps After Haeckel, System der Medusen, by with capitate tentacles, simple or permission of Gustav Fischer.
Thus the affinities of the hydranth are clearly, as Dendy points out, After Haeckel, System der Medusen, by permission of Gustav Fischer.
- View of the Oral Surface of one of the Leptomedusae (Irene pellucida, Haeckel), to show the numerous tentacles and the otocysts.
- Trophosome unknown; gonosome, free medusae of deep form, with radial canals branched in a feathery manner, and After Haeckel, System der Medusen, by permission of Gustav Fischer.
After Haeckel, System der Medusen, by permission of Gustav Fischer.
(After Haeckel.) c, Circular canal.
Haeckel regarded the whole structure as a glandular ectodermal pit formed on the exumbral surface of a medusa-person.
The difference between the theories of Haeckel and Chun is connected with a further divergence in the interpretation of the stem or axis of the cormus.
Haeckel regards it as the equivalent of the manubrium, and as it is implanted on the blind end of the pneumatophore, such a view leads necessarily to the air-sack and gland being a development on the ex-umbral surface of the medusa-person.
By Haeckel they are considered homologous with the umbrella of a medusa.
Thus a bract may be regarded, with Haeckel, as a modified umbrella of a medusa, a siphon as its manubrium, and a tentacle as representing a medusan tentacle shifted in attachment from the margin to the sub-umbrella; or a siphon may be compared with a polyp, of which the single tentacle has become shifted so as to be attached to the coenosarc and so on.
Haeckel, on the other hand, is in accordance with Balfour in regarding a Siphonophore as a medusome, that is to say, as a colony composed of medusoid persons or organs entirely.
Haeckel considers that the Siphonophores have two distinct ancestral lines of evolution: I.
In all other Siphonophores, the ancestral form was a Siphonula, a bilaterally symmetrical Anthomedusa After Haeckel, from Lankester's Treatise on Zoology.
Chondrophorida (Disconectae Haeckel, Tracheophysae Chun).
Haeckel, Lankester's FIG.
Haeckel 5 dealt with the whole problem of evolution.
Writings of Spencer embody the spirit of Descartes in the knowledge of our own day, and may be regarded as the Principes de la philosophic of the 19th century; while, whatever hesitation may not unfrequently be felt by less daring minds in following Haeckel in many of his speculations, his attempt to systematize the doctrine of evolution and to exhibit its influence as the central thought of modern biology, cannot fail to have a far-reaching influence on the progress of science.
2 This was done shortly afterwards by Professor Haeckel, who proposed the name Saururae for the group containing it.
(From Lankester, " Limulus and Arachnid.") Galeodes has been made the means of a comparison between the structure of the Arachnida and Hexapod insects by Haeckel and other writers, and it was at one time suggested that there was a genetic affinity between the two groups - through Galeodes, or extinct forms similar to it.
1834), who in 1866, seven years after the publication of Darwin's Origin of Species, published his suggestive Generelle Morphologic. Haeckel introduced into classification a number of terms intended to indicate the branchings of a genealogical tree.
Haeckel himself, with his pupil MikluchoMaclay, had in the meantime made studies on the growth from the egg of Sponges - studies which resulted in the complete separation of the unicellular or equicellular Protozoa from the Sponges, hitherto confounded with them.
On the ether hand, a survey of the facts of cellular embryology which were accumulated in regard to a variety of classes within a few years of Kovalevsky's work led to a generalization, independently arrived at by Haeckel and Lankester, to the effect that a lower grade of animals may be distinguished, the Protozoa or Plastidozoa, which consist either of single cells or colonies of equiformal cells, and a higher grade, the Metazoa or Enterozoa, in which the egg-cell by " cell division " gives rise to two layers of cells, the endoderm and the ectoderm, surrounding a primitive digestive chamber, the archenteron.
To the primitive two-cell-layered form, the hypothetical ancestor of all Metazoa or Enterozoa, Haeckel gave the name Gastraea; the em- bryonic form which represents in the individual growth from the egg this ancestral condition he called a " gastrula."
He is also responsible for the formulation of an important principle, called by Haeckel " the biogenetic fundamental law," viz.
But systematic zoology is now entirely free from any such prejudices, and the Linnaean taint which is apparent even in Haeckel and Gegenbaur may be considered as finally expunged.
The terms used for indicating groups are " Phylum " for the large diverging branches of the genealogical tree as introduced by Haeckel, each Phylum bears secondary branches which are termed " classes," classes again branch or divide into orders, orders into families, families into genera, genera into species.
- and are named, from north to south, Milne-Edwards deep, Krummel deep, Bartholomew deep, Richards deep and Haeckel deep. In the northeast the deeps are again few and small, but they are quite irregularly distributed, and not near the land.
Festschrift zum 70ten Geburtstage von Ernst Haeckel, 19(34) has restored the conditions existing in the lagoons and atoll reefs of the Jurassic sea of Solnhofen in Bavaria; he has traced the process of gradual accumulation of the coral mud now constituting the fine lithographic stones in the inter-reef region, and has recognized the periodic laying bare of the mud surfaces thus formed; he has determined the winds which carried the dust particles from the not far distant land and brought the insects from the adjacent Jurassic forests.
This law of recapitulation, subsequently termed the " biogenetic law " by Ernest Haeckel, was the greatest philosophic contribution of this period, and proved to be not only one of the bulwarks of the evolution theory but one of the most important principles in the method of palaeontology.
Haeckel) are formed.
Haeckel, "Das System der Medusen," Denkschriften med-natwiss.
Haeckel belongs to a slightly later time than the materialists hitherto mentioned.
Haeckel answers that it has no origin, because sensation is an inherent property of all substance.
But has Haeckel solved the problems of mind ?
The point is that neither Buchner nor Haeckel could on their assumptions recognize any force but force of body, or any mind but mind of body, or any distinct thing or substance except body.
Lastly, when a theory of the world supposes a noumenal power, a resistent and persistent force, which results in an evolution, defined as an integration of matter and a dissipation of motion, which having resulted in inorganic nature and organic nature, further results without break in consciousness, reason, society and morals, then such a theory will be construed as materialistically as that of Haeckel by the reader, whatever the intention of the author.
As an exponent of universal evolution Haeckel is more consistent than Spencer.
In thus endowing all matter with sensation like Haeckel he was not avoiding materialism.
According to Haeckel, matter is the universal substance, spirit its universal attribute.
Empedocles, Plato and Aristotle; Telesio, Bruno and Campanella; Leibnitz; the idealists, Schopenhauer and Hartmann, Fechner and Paulsen; and the materialist, Haeckel - all have agreed in according some sort of appetition to Nature.
It is doubtful, however, whether the conventional distinction between plants and animals will continue to be urged; and the suggestion of Haeckel that a class Protista should be established to receive the forms exhibiting both animal and plant affinities has much I.
Haeckel established the subclass Saururae, containing solely Archaeopteryx, in opposition to the Ornithurae, comprising all the other birds.
Haeckel distinguished autogeny and plasmogeny, applying the former term when the formative fluid in which the first living matter was supposed to arise was inorganic and the latter when it was organic, i.e.
Haeckel calls attention to the fact that a baby can hold a spoon with the big-toe as with a thumb.
Haeckel, Anthropogenie (Leipzig, 1874-1891), Eng.
Haeckel considers that there are three species.
Sativum is the ordinary cultivated wheat, of which Haeckel recognizes three principal races, spelta, dicoccum and.