426 



NATURE 



[March 2, 1905 



barrier was really part of the Antarctic continent. I have 

 no hesitation in saying 'yes,' and my reasons are these: 

 All our soundings between 60° and 70° S. were 2500 to 2700 

 fathoms. In 72" S. they shoaled to about 2300, fifty miles 

 from the barrier. Thirty-five miles from the barrier they 

 shoaled to 1400 and 1200 fathoms, and two miles from the 

 barrier to 160 fathoms. This alone should answer the 

 question in the way which I have done. Secondly, from 

 the vertical cliff of ice 100 to 150 feet in height which 

 bordered the ocean, the ice rose high inland in undulating 

 slopes and faded away in height and distance into the sky. 

 It was impossible to estimate the height of this field of 

 ice — the true inland ice of Antarctica — tut probably it was 

 many thousands of feet. Thirdly, seals and birds, which 

 up till now had become few in numbers, were seen in 

 myriads — penguins, especially emperors, many petrels, and 

 terns swarming in every direction — the inhabitants of the 

 beaches and rocky cliffs of some actual land not very far 

 distant. " 



.^fter the escape from the ice the Scotia turned north- 

 eastwards to continue the oceanographical survey of the 

 Weddell Sea. and had some very successful deep-sea 

 trawling in high southern latitudes — one haul in 71° 22' S. 

 16° 34' W. (1410 fathoms) yielding more than si.xty species 

 of animals. Ross's reported dce/i of 4000 fathoms no bottom 

 was shown conclusively not to exist, the whole Weddell Sea 



Fig. 3. -Weddell Seal-oft Coats Land. 



being apparently an almost level plain submerged between 

 2400 and 2700 fathoms. 



Pursuing a track northwards along the meridian of 

 10° \V., although encountering very heavy weather between 

 45° and 55° S. lat., some very interesting soundings were 

 obtained demonstrating the extension of the mid-Atlantic 

 ridge southwards as far as 52° S. lat. The diatom ooze 

 band extends between 48° and 58'^ S. ; to the south of this is 

 blue-mud, the detritus of the Antarctic ice-sheets, to the 

 north, globigerina ooze. 



On April 22 a landing was effected with considerable 

 difficulty on Gough Island, a previously unexplored outlier 

 of the Tristan da Cunha group. This apparently entirely 

 volcanic island is richly clad with vegetation, but the ex- 

 tremely precipitous nature of the ground prevented any 

 extensive survey being made, though two new species of 

 plants were obtained — a Cotula and an Asplenium ; and 

 amongst the birds two entirely distinct and new species of 

 finches. .Shallow water collections were got off the shore 

 by means of the dredge and trap. Between Gough Island 

 and Cape Town several soundings were taken between the 

 parallels of 39° and 40°. 



On February 8 of the present year, the Argentine sloop 

 Uruguay returned to Buenos Aires from the South Ork- 

 neys, having brought back safely Mr. Mossman and his 

 party, and landed a fresh staff there. The station is being 

 contiiiued for meteorological and magnetic work, and a 

 complete outfit of self-recording magnetic instruments has 

 been installed. This work is in connection with the 

 systematic magnetic survey of .Argentina which is at pre- 

 sent being undertaken. 



NO. 1844, VOL. 71] 



THE EARLY HISTORY OF SEED-BEARING 

 PLANTS, AS RECORDED IN THE CARBONI- 

 FEROUS FLORA.' 

 i\ LARGE number of the fern-like fronds of Carboniferous 

 * age, including many whole genera, as Neuropleris, 



.Methopteris, Callipteris, Linopteris, &c., have never been 

 found to offer any satisfactory indications of a fern-like 

 fructification. Some suspicion was thus awakened that such 

 fronds may have belonged to plants other than true ferns. 



Positive evidence first came from the anatomical side. 

 The vegetative structure of Ly ginodcndron Oldhamium was 

 completely worked out, chiefly by Williamson, and proved to 

 present a combination of filicinean characters with those of 

 cycadaceous gymnosperms. Similar results were attained 

 in other genera, as Heterangium, Medullosa, Calamopitys 

 and Protopitys, and hence the class Cycadofilices was founded 

 to embrace these apparently intermediate forms. Decisive 

 evidence as to the fructification was first obtained in 1903, 

 when it was shown by Prof. F. W. Oliver, in collaboration 

 with the lecturer, that the seed Lagenostoma Lomaxi agreed 

 so closely in certain structural features with the associated 

 Lyginadeiidron Oldhamium as to leave no doubt that the one 

 belonged to the other. Observations on other Lagenostomas 

 support this conclusion and show that the seeds were borne 

 on modified fronds. It thus appears that the family Lygino- 

 dendrre consisted of seed-bearing 

 plants, allied to the cycads, but re- 

 taining filicinean characters ; their 

 foliage was of a sphenopteroid type. 

 In another extensive family, that 

 of the Neuropterideje, precisely 

 analogous conclusions have bfen 

 reached. Here, too, the anatomical 

 evidences indicated a position inter- 

 mediate between ferns and cycads. 

 In the case of Neiiropteris ketcro- 

 phylla it has been proved by Mr. 

 Kidston that large seeds, referred by 

 him to the genus Rhabdocarpus of 

 Goeppert and Berger, were borne on 

 the frond. There are reasons for be- 

 lieving that Trigonocarpon was the 

 seed of .Alethopteris, and M. Grand- 

 'Eury, on the ground of extensive 

 observations on the distribution of 

 fronds and seeds, is led to conclude 

 that the Neuropterideae generally 

 were seed-bearing plants, of cycadean affinity. 



It has been proposed to group these fern-like seed-plants, 

 which in Carboniferous times probably exceeded the ferns 

 themselves in number, under the name Pteridospermeie. 

 Their relation to the fern-phylum is evident from many 

 points in their structure, apart from the relatively un- 

 important external characters. 



Other seed-bearing plants of the Carboniferous flora have 

 long been known, notably the Cordaitea?, great trees with 

 large simple leaves, totally different from the Pterido- 

 spermejE in habit, and with little indication of fern-like 

 structure. The fructifications also are of a more advanced 

 character than those of the pteridosperms. In the structure 

 of the seeds, however, and in some anatomical points, a 

 certain affinity, though a distant one, with that family is 

 suggested. It is probable that the Cordaitere ultimately 

 sprang from the same stock as the Pteridosperme.-r, though 

 at a very remote period. On the other hand, there is reason 

 to believe that the Conifera^, appearing at the close of the 

 Pal.Tjozoic period, were related to the Cordaitea:. It is thus 

 indicated as probable that the gymnosperms generally were, 

 in a wide sense, of monophyletic origin, as having been 

 ultimately derived from a common stock allied to the ferns; 

 in a narrower sense they may be termed polyph)letic, as 

 having sprung from this common stock at different points. 



.Althougn, as we now know, certain of the Palaeozoic 

 lycopods had likewi.se attained to the production of a seed- 

 like fructification, there is at present no satisfactory evidence 

 fur connecting the members of this phylum with any of the 

 groups of seed-bearing plants which have come down to our 

 own day. 



^ Abstract of the Wilde Lecture deliveretl before the Manchester Literary 

 and Philosophical Society on February 28 by Dr. D. H. Scott, F. R.S. 



