October 27, 1910J 



NATURE 



551 



entiation — the main problem — is determined by external 

 factors, such as the physical and chemical environment, 

 and by internal factors, e.g. the initial structure of the 

 germ and the interaction of developing parts. Experiments 

 prove that there exist in the cytoplasm definite organ- 

 forming substances arranged in a definite manner, and 

 sometimes stratified and graded. Such an arrangement 

 accounts for the observed progressive restriction of the 

 potentialities of parts. During cleavage these substances 

 are segregated into cells, but the order in which this takes 

 place seems to be immaterial ; the essence of segmentation 

 is the reduction of the ratio of cytoplasm to nucleus. 



In regeneration — the production of a whole structure by 

 a part in a differentiated organism — similar processes and 

 factors may be observed. The regenerate often differs 

 quantitatively or qualitatively (heteromorphosis) from the 

 original ; reversal of polarity is a special case of the latter. 

 Features common to all regeneration are : — (i) the cover- 

 ing of the wound ; (2) cell multiplication (resulting in the 

 reduction of the cytoplasm-nucleus ratio) ; (3) growth, 

 always at right angles to the cut surface, and at a rate 

 which alters like the ontogenetic rate ; (4) differentiation, 

 which usually follows the ontogenetic order, but may differ 

 from it (anomalous behaviour of germ layers). Of the 

 external factors concerned little is known except that the 

 actual injury is the prime stimulus ; the internal factors 

 are: — (i) interaction of parts; (2) size (there is a minimal 

 size) ; (3) degree of differentiation (power of regeneration 

 decreases with age) ; (4) level or material (necessarily 

 cytoplasmic, since the nuclei are all alike) ; (5) polarity, 

 which may be expressed in terms of a graded stratifica- 

 tion of materials. The adult organism contains the same 

 organ-forming substances as w'ere present in the germ, and 

 arranged in a similar way; the difficulty is that the 

 former is divided into cells. A further difficulty is pre- 

 .sented by the anomalous behaviour of the germ layers and 

 by the fact that a part, in w'hich these substances exist, 

 ex hypothesi, in other than the correct proportions, can 

 yet form a whole. This indicates that the problem is 

 fundamentally one of assimilation; and Dr. Jenkinson 

 pointed out, in conclusion, that metabolism and regenera- 

 tion in the protozoa are solely dependent on the presence 

 of the nucleus. 



Prof. C. S. Minot gave an address, which, however, 

 cannot be summarised in a few lines and without the aid 

 of diagrams, dealing with the relations of the primitive 

 streak, blastopore, neurenteric canal, and medullary folds 

 in various vertebrates. 



Cytological papers by Prof. Hartog and Dr. Edwin 

 Hindle were contributed to the joint meeting of Sections 

 D and K, and Dr. E. J. Russell read, to the joint meeting 

 of -Section D and .Sub-section B, a paper on the part 

 played by micro-organisms, other than bacteria, in deter- 

 mining soil fertility. .\ notice of these papers will be 

 found in the reports of the proceedings of Section K and 

 of Sub-section B. J. H. Asuvvorth. 



GEOGR.iPHY AT THE BRITISH ASSOCIATION. 

 T .\' his presidential address on some of the more pressing 

 needs of geography. Prof. A. J. Herbertson spoke of 

 geographical classification and terminology especially with 

 regard to the genetic classification of land forms, and gave 

 suggestions as to a suitable form of notation. In speaking 

 of geographical units, he laid great stress on the signi- 

 ficance of vegetation to the geographer, for which a study 

 of climatic regions is as necessary as a study of morpho- 

 logical ones. Dr. Herbertson 's address was printed in full 

 in Nature of September 22. 



The first paper was by Dr. J. D. Falconer, on the origin 

 of some of the more characteristic features of the topo- 

 graphy of northern Nigeria. The rivers belong to two 

 great hydrographical systems, the Niger-Bcnue and the 

 Chad systems. The watersheds are lofty plains of a 

 iTiature topography, while the prominent hills exert only a 

 secondary influence on the- drainage system. In their upper 

 and middle courses the rivers flow over open plains the 

 surface of which is diversified by numerous isolated granite 

 domes, turtlebacks, and inselberge In their lower courses 

 they often flow in deep valleys bounded on either side by 

 NO. 2139, VOL. 84] 



ranges of flat-topped hills. These hills have been carved 

 out of horizontal sedimentary rocks, while the isolated 

 domes of the upper plains are clear evidence of a crystalline 

 floor. The peculiar character of the river valleys is entirely 

 due to the recent origin of the whole river system. 



Two papers were read by Dr. W. S. Bruce, the first on 

 Prince Charles Foreland, Spitsbergen, the second on his 

 plans for a second Scottish National Antarctic Expedition. 

 During the summers of 1906, 1907, and 1909, Prince 

 Charles Foreland was explored by Scottish expeditions 

 under Dr. Bruce 's leadership. The expedition of last year 

 in the steam-trawler Conqueror was on the most extensive 

 scale of the three, and practically completed the exploration 

 of the island. The chief object of the worlc was to make a 

 detailed map of the Foreland on a scale of two miles to the 

 inch. This map is a continuation of similar work carried 

 on by the Prince of Monaco on the mainland, and by 

 Norwegians under his direction. The island is about fifty- 

 four miles long and from three to seven and a half miles 

 broad, with an area of 262 square miles. .\n almost con- 

 tinuous range of hills, the northern Grampians, occupies 

 the northern two-thirds of the island, and rises to 3800 feet 

 in Mount Monaco and 3300 in Mount Jessie. Separating 

 these from the Ross heights at the southern end is an 

 extensive low-lying part, called the Foreland Laichs, ap- 

 parently a raised sea bottom. On the cast an almost 

 continuous ice-sheet flows from the northern Grampians to 

 Foul Sound, but the west is free from glaciers. A bathy- 

 metrical survey of Foul Sound demonstrated a bar towards 

 the northern end over which vessels drawing more than 

 12 or 15 feet have difficulty in finding a passage. The 

 rocks are mainly Hekla Hook schists and graywack^s, 

 with a small pocket of tertiary beds on the east near 

 Ferrier Haven. The completed topographical map will be 

 one of the most detailed ever made ot any part of the polar 

 regions. 



The plans for a second Scottish National Antarctic Ex- 

 pedition were first published in 1908, but have since been 

 matured and elaborated. It is intended first of all to com- 

 plete the bathymetrical survey of the South .Atlantic 

 between Buenos Aires and Cape Town, and Cape Town 

 and the South Sandwich group. A course will then be set 

 for Coats Land, discovered by Dr. Bruce in 1904. Wherever 

 a suitable landing-place can be found along this coast, the 

 base of the expedition will be established. From this base 

 Dr. Bruce will endeavour in the following summer to 

 cross -Antarctica via the Pole to Victoria Land, a long 

 journey, but one which for the greater part of the way 

 will be over entirely new ground, and must result in con- 

 siderable light being thrown on the complex and difficult 

 problem of the structure of -Antarctica- After landing Dr- 

 Bruce and his party on Coats Land the ship will continue 

 eastward, conducting oceanographical work along the edge 

 of -Antarctica- On this work Dr. Bruce lays particular 

 stress. It is also hoped to map in the " missing " coast 

 line between Coats Land and Kaiser Wilhelm Land. After 

 refitting at Melbourne, the ship will proceed southward to 

 pick up Dr. Bruce at some point on Victoria Land, and 

 then make for New Zealand- Thence via Cape Horn a 

 course will be made for Coats Land to embark the 

 remainder of the party left there, who will have been 

 conducting meteorological work during two winters and 

 one summer- From Coats Land the expedition will return 

 home- The exploratory work will be conducted entirely in 

 the Weddell and Biscoe quadrants, for Dr- Bruce recog- 

 nises that the Ross sea and adjacent lands are the special 

 province of Captain R- F- Scott and Sir Ernest Shackleton- 

 The total cost of the expedition will be about 50,000/- 



In the afternoon Captain J- K- Davis, of Sir Ernest 

 Shackleton's recent expedition, read a paper on the voyage 

 of the Nimrod from Sydney to Monte Video- _ Attempts 

 were made to locate certain doubtful islands, viz.. Royal 

 Company Islands, Emerald Island, the Nimrod group, and 

 Dougherty Island. None of these islands were found, and 

 deep soundings were obtained on or near their supposed 

 positions. They may therefore be removed from the 

 chart. A visit to Macquarie Island resulted in some in- 

 teresting collections. The two-hourly meteorological ob- 

 servations taken during this voyage, which extended through 

 Mav and June, should prove of great importance. 



Friday morning was devoted to a joint meeting with 

 Section ' C. Three of the papers dealt with local geo- 



