[Tou v., Ko. 1
��water coutaiDing powdered cannlnp. It waaaotlceil, tliat, although ail ilie cells touk up the carmine, the epithelium of the cillnted chambers soon ejected the granules, while the cells o( the upper Burface of the subdermal earit; gave tbern ofl to the amoeboid wandering cells of the mesoderm, which, after the; hail partly digested the carmine, transmitted it to the cells of the ciliated chnmlwrs for ejection. He con- cluded, therefore, that although all the cell! had the power of absorption, as is the case in man, still the digestive function in the species upon which he ez- periniented was cenlralwed in the upper wall «f the subdermal cavities. Other authors have held differ- ent views; and in a subsequent paper be himself has concluded that It cannot yet be decided whether sponges digest with the ectoderm or the entoderm, Uiough be considers it not improbable that both layers may have that function. His papers will be found in the Proceedings of the Linneau society of New South Wales.
R. von Lendenfeld has also described in the Annalii and magivclne 0/ natural hlntory for December, 1S84, a new variety of Medusa which may prove to be a new species evolved within the last forty year*. The species is Crambessa mosnica, which Huxley lu 1845 described from Sydney, Australia, as blue to gray, but which is now found in this locality distinctly brown in color, due to a parasitic alga which infests Ihe flesh near the surface. The evidence is sufficient to cause Ton Lendenfeld to state that it is probable that this new variety has been born since Huxley described it in 184G. He also mentions the case of another Medusa (Cyanea annaakala) which has hitherto been found only at Port Phltip, where It is abundant, hut which has recently been found at Port Jackson in warmer water. Those in the latter place differ from the typical species in b«ing much larger, and, besides, in possessing deep-purple pigment-cells around the mouth-oms, which iie thinks may be able to perceive light. He makes a new variety from this variation of
��THE ANATOMY AND PHYSIOLOOY OF THE BRAIN IN THEIR RELATION TO MENTAL DISORDERS.
Treatises upon insRnity have been appear- ing recently in quick euccession, both in this coiiiilry and abroad. Tbere is none, however, which will commnnd more notice, and prove more Bu^esti>'e, tbnn this work.
Professor Meynert, who hns been at the head of the department of psycliiatry in the Univer- sity of Vienna for the past fifteen years, was one of the 01*^1 to advance the opinion that a. Btudy of mentiil disease roust be precedeenran(!c of iiis first articles in Strieker's ' Handbook of histology ' in lti70, he baa been the chief authority in Germany : and almost every one of the younger scientific men who have done original work in this department has been imbued with his enthusiasm by personal contact with bim in his laboratory. Within a hundred and twenty-five pages he has succeeded in giving a clear statement of the complex subject of the arrangement and relations of the gray masses and white con nee ting- fibres which make up the brain. An important aid to the comprehension of the structure will be found in liie numerous escellent drawings of dissections and of microscopic sections.
The gray matter of the nervous system is the part in which sensory impulses are received and registered, and in which motor impulses are initiated. The white matter is made up of threads which transmit the impulses without raoilifying them. The structure and functions of the gray matter differ in different ^larts; simple functions being performed by that in the spinal cord, more complex functions in the gray masses within the brain, the moat complex and the conscious functions being assigned to the layer which is spre.id out upon the surface of the brain, and which is thrown into folds hy its convolutions. Each part of the surface at the body is in anatomical connection, by means of nerve-Bbres, with its own part of the aurfaoe of the brain ; and ihua it is not diflScult lo im- agine a projection of a map of the body upoa the brain-cortex. The fibres which act in this manner to bring the external world into con- sciousness are named by Meynert ' the pro- jection system of tracts.' This 'projection system ' was announced in ISTO. and was the starting-point to which all the recent discov- eries regarding the localization of functions in various regions of the brain can be traced. It is to-day the ground-work for many arguments in favor of the theory of localization, — a the- ory to which Meynert gives his hearty support.
At present, investigations in bra in -anatomy
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