468 THE POPULAR SCIENCE MONTHLY. 



going from the periphery of the convolutions to the central gray col- 

 umn. The nervous influx first goes into those two large ganglions of 

 gray substance, the corpora striata and the o^ytic layers. Probably 

 these organs transform the phrase thought into voluntary movement. 

 From the corpora striata the vibration is transmitted along the cen- 

 tral axis to the olivary bodies, which are the coordinating aj)paratus, 

 and which regulate and direct the movement. From the olivary bodies 

 proceed nerves to the lips, the larynx, the tongue, the pharynx, the 

 palate all the vocal organs concerned in production of language. 

 Pathological facts teach us that these difiereut a2)paratuses may be 

 destroyed separately, and there is then involved the absolute loss of 

 such and such a function. 



Thus in a case recorded by Dr. Winslow, the man had retained the 

 faculty of language; he could write the* words and phrases which he 

 thought of ; but, when he tried to speak, he only uttered confused 

 sounds. In this instance the olivary bodies were alone afiected. The 

 faculty of language remained intact; the vocal apparatus was not 

 injured ; but the apparatus of transmission was profoundly altered. 



In other cases, again, it is the organ of thought itself that is dis- 

 eased. There is an afl"ection well known to physicians who study the 

 insane, and which is called general paralysis. This disease begins in 

 the periphery of the convolutions, which are devoured (so to speak) 

 by a slow inflammation characterized by intermittent extensions. One 

 may take account of the disorders it causes by the state of intelligence 

 of the patients. At first the inflammation produces an intellectual ex- 

 citation, which expresses itself in mad acts. Each time a fresh access 

 of madness is observed, one may pretty surely infer a new extension 

 of the disease. But at length, when the whole outer surface of the 

 hemispheres is destroyed, there is no longer either thought, or will, 

 or instinct ; the unhappy subjects are plunged in a state of somno- 

 lence and stupor, from which nothing can rouse them. They do not 

 speak, because the organ of thought no longer exists. 



It is pi'obable, then, that between the organ of thought and tlie 

 vocal oro-an there is a third orocan the or^an of words, and it is a 

 lesion of this which properly constitutes aphasia. English Mechanic. 



-- 



ARCTIC ICE-TRAYELS. 



By CLEMENTS E. MAEKHAM, Y. E. S. 



FORMERLY exploration in the arctic regions was entirely per 

 formed by ships. On one or two occasions only were sledge-par 

 ties dispatched for the purpose of discovery, and then on a very 

 reduced scale. During the search expeditions, however, after Sir 

 John Franklin and his gallant companions, the system of sledge-trav- 



