January i, 1920] 



NATURE 



453 



caused suspicion at first to fall on articles of diet. 

 Thus some observers were struck by a similarity to 

 cases of botulism, a disease due to the poisons of a 

 bacillus which can flourish in foodstuffs kept out of 

 contact with air, as when meat or vegetables are im- 

 mersed in a weak pickle. Others suggested that 

 some essential accessory factor had been lacking in the 

 diet, so leading to a "deficiency" disease, perhaps 

 analogous to beri-beri, in which nervous symptoms 

 are prominent from afi'eclion of the peripheral nerves. 

 But the wide area over which cases were distributed, 

 and the rarity with which more than a single member 

 was attacked in any one family, almost excluded such 

 theories of causation. 



Further clinical investigation, and especially patho- 

 logical examination, established the close resemblance 

 between the new disease and the well-known condition, 

 acute poliomyelitis or infantile paralysis. In both 

 diseases the essential pathological feature consists in 

 microscopic areas of inflammation, with cellular in- 

 filtration, consisting largely of round cells, in the 

 perivascular Ivmphatic sheaths and in the grey matter. 

 In Encephalitis lethargica these changes were most 

 noticeable in the upper part of the pons and in the 

 basal nuclei. In the affected areas the nerve-cells 

 showed the usual changes indicative of degeneration. 

 In addition, Marinesco found degeneration of the 

 Purkinje cells of the cerebellum in the two cases 

 examined bv him ; such changes are similar to those 

 observed bv Mott in shell-shock, and previously studied 

 bv Crile, who considered them an expression of cellular 

 exhaustion. 



Thus the nervous lesions did not at all resemble 

 those originally investigated by Marinesco in botulism. 

 On the other hand, there are certain well-marked 

 differences from infantile paralysis as regards the 

 localisation of paralysis, which in the new disease 

 mainlv affects the cranial centres, while the spinal 

 cord is commonly the site of lesions in infantile 

 paralysis ; also there is a practicallv equal incidence 

 of the disease at all ages, whereas infantile paralysis 

 affects mainly children and young adults. But such 

 differences are possiblv within the limit of variations 

 which mav occur in a clinical " entitv " or "syndrome," 

 since modern investigation of infective diseases in 

 general has taught that the number of " tvpical " cases 

 of anv condition mav constitute a variable, and some- 

 times relatively small, proportion of the total number. 



The experimental results are' of greatest importance, 

 however, as tending to show that the two diseases are 

 distinct in their causation. It has been well estab- 

 lished bv various observers in different parts of the 

 world that in cases of infantile paralysis the central 

 nervous svstem especially harbours the virus, and that 

 the disease can be transmitted to monkevs bv intra- 

 cerebral inoculation with glycerinated emulsions of 

 brain or solnal cord. On the other hand, Mcintosh 

 consistentiv failed to transmit the new disease to 

 monkevs bv injecting emulsions of nervous tissue from 

 cases under similar conditions to those which are suc- 

 cessful in poliomvelitis. 



The disease, after ofjtruding itself in the spring and 

 earlv summer of iqi8. has again relapsed into 

 obscurity for the time being. The valuable work in 

 this report has outlined the natural historv of the 

 manifestations, but the failure to reproduce the 

 disease exnerimentallv or to identifv any micro- 

 organism as ronstantlv associated with it has pre- 

 ^•ent^d the elaboration of a basis for dealing with a 

 future outbreak. It mav be presumed that, like 

 infiintile paralvsis. it is a disea.se to which the 

 maioritv of individuals are relativelv resistant, and 

 that henlthv carriers, who harbour the virus in the 

 nose and pharvnx without themselves suffering from 



NO. 2618, VOL. 104] 



ill-effects, probably play a large part in dissemination. 

 The' practically simultaneous occurrence of En- 

 cephalitis lethargica in this country, France, and 

 .Austria is another "of the unaccountable manifestations 

 of the disease. C. H. B. 



T' 



EXPLORATION OF NORTHERN 

 GREENLAND. 



HE second Thule Expedition to northern Greenland 

 in 1916 to 1918, under the leadership of Mr. 

 Knud Rasmussen, is the subject of articles in the Geo- 

 graphical Review for .August and September (vol. viii., 

 Nos. 2 and 3). With Thule on Melville Bay as a base, 

 the main party of the expedition left on a long sledge 

 journey to explore the northern coast of Greenland 

 between Robspn Channel and Peary Land. This coast 

 had been only roughly sketched by Pearv on one of 

 his northern journeys. Mr. Rasmussen 's party charted 

 it in detail between St. George's Fjord and be Long 

 Fjord. It was found that Nordenskjold Inlet, at one 

 time supposed to be the end of the so-called Peary 

 Channel, but disproved in 1907 by Mylius Erichsen, is 

 a short fjord ending in a glacier. The distribution of 

 ice-free land was found to be the opposite of what 

 was before believed to be the case, the land round 

 St. George's Fjord being ice-free, and that round 

 Nordenskjold Inlet ice-covered. Mr. Rasmussen 

 failed to find any ruins of Eskimo houses in that dis- 

 trict, or any signs that Eskimo had ever migrated 

 round the north coast of Greenland. This was 

 previously supposed to be the route by which Eskimo 

 at one time reached the cast coast, where traces of 

 camps and villages are numerous. Musk-oxen mav 

 have migrated in small herds round the north, but the 

 general conditions of hunting are so poor that Eskimo 

 are unlikely to have been attracted to the route. The 

 ice-free areas are not large enough to furnish sufticient 

 game for a wandering tribe, and the conditions of thi 

 pack-ice along the north-west coast make hunting on 

 the sea impossible. Mr. Rasmussen believes that the 

 east coast natives travelled from the west b\- Cape 

 Farewell, and that reconnoitring parties of hunters 

 went so far north as Independence Fjord. The 

 botanical work of Dr. Thorild Wulff, who died from 

 starvation, was important, and Mr. Lauge Koch ob- 

 tained valuable geological results. The new map of 

 the coast, of which a sketch is added to the article, 

 was carefully prepared, fortv observations of latitude 

 and fortv determinations of longitude being taken. 



AQUATIC FAUNA OF SEISTAN. 

 TTNDER the auspices of the Indian Medical 

 ^ Research Fund, Dr. N. .Annandale and Mr. 

 S. W. Kemp undertook in November, December, 

 and January, igi8-iq, an expedition to Seistan 

 and Baluchistan with the object of discovering 

 whether the disease Bilharziasis (or Schistoso- 

 miasis) occurred in Seistan, and, in particular, 

 whether any of the known moUuscan hosts of 

 the parasite were to be found in that region. So 

 far as the medical part of the inquiry was concerned 

 the results were negative, but ths opportunity was 

 taken to make a collection of the limited aquatic 

 fauna of the country. The zoological results of the 

 expedition are now in course of publication as a 

 special volume of the "Records of the Indian 

 Museum " under the title of " Report on the .Aquatic 

 Fauna of Seistan." In an introductory essay Dr. 

 .Annandale describes the physiographical conditions of 

 the Hamun-i-Helmand, the basin into which the 



