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Chorda dorsalis. Chough, red beak of the. Chromidae, frontal protuberance in male; sexual differences in colour of. Chrysemys picta, long claws of the male. Chrysococcyx, characters of young of. Chrysomelidae, stridulation of. Cicada pruinosa. Cicada septendecim. Cicadae, songs of the; rudimentary sound-organs in females of. Cicatrix of a burn, causing modification of the facial bones.
It is only within recent years that medical men have recognized the preponderant part played by acquired or inherited syphilis in producing general paralysis, which so largely helps to fill lunatic asylums, and tabes dorsalis which is the most important disease of the spinal cord.
The tail is lost, as there is no further use for it. It undergoes a fatty degeneration, and disappears with the chorda dorsalis. The tailless body changes into an unshapely tube, and, by the atrophy of some parts and the modification of others, gradually assumes the appearance we have already described.
There is no trace in the fully-developed Ascidia of a chorda dorsalis, or internal axial skeleton. It is the more interesting that the young animal that emerges from the ovum HAS a chorda, and that there is a rudimentary medullary tube above it. The latter is wholly atrophied in the developed Ascidia, and looks like a small nerve-ganglion in front above the gill-crate.
Anthus pallescens, VIG. and HORSF. Cincloramphus cantillans, GOULD. Petroica multicolor, SWAINS. phoenicea, GOULD. Goodenovii, JARD. AND SELB. rosea, GOULD. bicolor, SWAINS. Drymodes brunneopygia, GOULD. Zosterops dorsalis, VIG. and HORSF. Pardalotus punctatus, TEMM. striatus, TEMM. Dicaeum hirundinaceum Estrelda bella. temporalis.
In the lunar or weekly recurrent periods of some of our functions we apparently still retain traces of our primordial birthplace, a shore washed by the tides. At about this same early period the true kidneys were replaced by the corpora wolffiana. The heart existed as a simple pulsating vessel; and the chorda dorsalis took the place of a vertebral column.
I can learn nothing of the habits of the sharks Hexanchus, Heptanchus, and Echinorhinus, but Müller describes them as possessing a persistent chorda dorsalis. It may be they have the habits of the tope, but other sharks are amongst the very swiftest and most active of fishes. Mr.
There are, as has been pointed out by Mott, a leading authority in this matter, five ways in which syphilis affects the brain and nervous system: by moral shock; by the effects of the poison in producing anæmia and impaired general nutrition; by causing inflammation of the membranes and tissues of the brain; by producing arterial degeneration, leading on to brain-softening, paralysis, and dementia; as a main cause of the para-syphilitic affections of general paralysis and tabes dorsalis.
Taking advantage of the space of the plate, figures of the following species from the same country, which have not hitherto been illustrated have been added. They were described or noticed in the list before referred to. Cystignathus dorsalis, t. 1. f. 2. Phryniscus Australis, t. 2. f. 1. DUM. AND BIB. E. GEN. viii. 725. Bombinator Australis, GRAY, PROC. ZOOL. SOC. 1838. 57. III. Mr.
In this tail is developed starting from the primitive gut a cylindrical string of cells, the fore end of which pushes into the body of the larva, between the alimentary canal and the neural canal, and is no other than the chorda dorsalis. This important organ had hitherto been found only in the Vertebrates, not a single trace of it being discoverable in the Invertebrates.
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