284 



NA TURE 



[7ufyi 9 , 1883 



rocks of Logan, called Animikie, Nepigon, and Keweenian, by 

 Dr. Hunt, and the unconformity of the Animikie divisions to 

 the underlying Huronian, by some geologists in the United 

 States supposed to be of the same age. (2) Mr. W. Saunders, 

 of London, Ont., " On the Influence of Sex on Hybrids among 

 Fruits." This paper gave some of the results of Mr, Saunders's 

 experience in hybridising fruits. The facts cited confirmed the 

 view that the influence of the female is more strongly expressed 

 in the habit, character of growth, and constitution of the vine, 

 bush, or tree, while the influence of the male is more distinctly 

 seen in the form, colour, and quality of the fruit, and in the case 

 of hybrid grapes in the size and form of the seeds also. (3) 

 Mr. G. F. Mathew, of St. John, N.B., on "The Method of 

 distinguishing Lacustrine from Marine Deposits," based on care- 

 ful observations on the deposits now taking place and accumu- 

 lated since the Pleistocene period in lakes in New Brunswick. 

 (4) Dr. J. A. Grant, of Ottawa, on " The Inferior Maxilla of 

 the Phoca Grcenlandica from Green's Creek, near Ottawa. (5) 

 Principal Dawson, of Montreal, on " Spores and Spore-cases, 

 from the Erian Rocks." The author referred to the discussion 

 many years ago by the officers of the Geological Survey of a 

 bituminous shale at Kettle Point, Lake Huron, of vast numbers 

 of minute round disks, which were recognised as the spore-cases 

 of some cryptogamous plant, and named Sporangites Huronensis. 

 More recently Prof. Orton, of Columbus, Ohio, Prof. Williams, 

 of Cornell, and Prof. Clarke, of Northampton, have found in 

 the Enan and Lower Carboniferous shales of Ohio and New 

 York beds replete with these organisms, and Prof. Orton has 

 shown reason to believe that they are connected with filamentous 

 stems found in the same layers, and also that they have contri- 

 buted largely to the bituminous matter present in the shales in 

 which they occur. Similar bodies have also been found 

 associated with the curious plants known as Ptilophyton and 

 Trochophyllum. Still more recently specimens from the Erian 

 of Brazil have been sent to the author by Mr. Darby, of the 

 Brazilian Geological Survey, which seem to throw additional 

 light on these bodies. They are oval or rounded or in the form 

 of flattened sacs, containing numbers of rounded disks, and so 

 closely resembling the utricles or spore sacs of the Rhizocarps as 

 to make it extremely probable that they belonged to plants 

 of this class. Should this conjecture be sustained by sub- 

 sequent inquiries it would show that this peculiar group 

 is of much greater antiquity than hitherto supposed, and 

 that these plants were extremely abundant in the shallow 

 waters of the Erian period. Dr. Dawson suggests the 

 probable relation of these singular fruits not only with the 

 Ptilophyton, but also with the other Erian and Silurian plants. 

 (6) E. Gilpin, jun., on "The Folding of the Carboniferous 

 Group in the Maritime Provinces." The author described each 

 of its great subdivisions as exposed at various points, and showed 

 that during the Carboniferous period, in addition to the conti- 

 nental changes of level, giving rise to conditions of deposition 

 characterising the carboniferous limestone, millstone, grit, &c. 

 there were extensive foldings of a more local character, appa- 

 rently in some cases marking the closing of these oscillations, 

 These foldings and their subsequent denudations have played an 

 important part hitherto but little studied in modifying the condi- 

 tions arising from the larger and more extended movements 

 which have hitherto principally received attention, and present 

 the district as being far from an universal state of quiet and 

 regular succession during the Carboniferous age. (7) Prof. R. 

 Bell, M.D., on "The Causes of the Fertility of the Land 

 in the Canadian North-west Territories." In the Canadian 

 North-west a vast fertile tract stretches, with certain exceptions, 

 from the Red River Valley to the Liard River, a distance of 

 some 1400 miles. The soil of this tract was characterised as a 

 dark loam, of varying depth, and of a nearly homogeneous con- 

 sistency. The primary cau-e of the fertility of this region was 

 the abundance of the underlying crude material out of which a 

 finished soil could be made. This was derived partly from the 

 widespreading crustaceous marls which were nearly coextensive 

 with the fertile tract, and probably from the drift daring the 

 Glacial period. Dr. Bell next considered the process by which 

 the black loamy soil was formed out of this subsoil, and he con- 

 sidered that the main agency was the work of moles and other 

 burrowing animals. Worms appeared to be absent in the 

 North-west, owing principally to the frost penetrating into the 

 ground beyond the depth to which worms can burrow, but the 

 moles and the ground squirrels, or gophers, more than make up 

 for their absence. In the fertilised tracts the old and new mole- 



hills cover the whole surface, rendering it "hummocky," which 

 may be easily observed after the prairie has been swept by a fire. 

 The badgers often did what was compared to subsoil ploughing. 

 All the animals referred to were very active in the autumn, 

 digging many more burrows than appeared to be of any use to 

 themselves. Each hummock thrown up by the moles covered 

 about a square foot, and buried all the grass, &c, on this space. 

 In this manner large quantities of vegetable matter were ulti- 

 mately irrcorporated with the soil. The work of the moles also 

 acted in another way in refining the soil, for they left behind the 

 stones and coarse gravel, so that these in time became sunk 

 beneath the layer of mould produced. By an interesting coin- 

 cidence at the season when the burrowing animals are most 

 active, the prairie vegetation is mature, and contains the largest 

 amount of substance. The coldness of the scil during the most 

 of the year tended to preserve the organic matter in it. While 

 the circumstances given were the direct cause of its fertility, the 

 ultimate reason was perhaps to be looked for in the climate of 

 the North-west, for to this was due the growth of the vegetation 

 which formed the manure and the food of the little workers which 

 mingled it with the soil. Thus we could trace a mutual 

 dependence of the circumstances which together have given 

 to our North-west Territories that surpassing fertility of 

 soil which cannot fail to attract to it a vast population. 

 (8) Dr. G. M. Daw-son, on "Notes on Triassic Rocks of the 

 West," discussing the question as to the Triassic or Jurassic age 

 of deposits found in British Columbia and the Rocky Mountains, 

 and their correlation with the deposits of similar age in the 

 territory of the United States. (9) Prof. L. W. Bailey, Ph.D., 

 Fredericton, on "The Occurrence of Indian Relics in New 

 Brunswick," probably deposits found at an old camping ground 

 of the Malicete Indians. (10) Dr. T. Sterry Hunt, on "Studies 

 on Serpentine Rocks." (11) Prof. J. Macoun, on "Notes on 

 Canadian PolypetalDe." The geographical distribution of these 

 plants in Canada was discussed, and interesting facts were ad- 

 duced in connection with the number of species and genera in 

 each order which showed certain relations between the present 

 flora and that which had existed in the Tertiary period. (12) A 

 paper by Mr. R. Chalmers was communicated by Principal 

 Dawson, in which facts were stated showing important erosion 

 on the coast of the Bay des Chaleurs by floating ice in the 

 modern and later Pleistocene periods. 



Dr. Selwyn, Prof. Lawson of Halifax, and J. F. Whiteaves, 

 were re-elected president, vice-president, and secretary of the 

 Section respectively. 



The following were the officers elected by the Society for the 

 present year : — President, Hon. P. J. O. Chauveau, LL.D. ; 

 Vice-president, T. Sterry Hunt, F.R.S. ; Hon. Secretary, J. G. 

 Bourinot, B.A. ; Hon. Treasurer, J. A. Grant, M.D. 



THE HYPOPHYSIS CEREBRI IN TUNIC ATA 

 AND VERTEBRATA^ 



TN most simple Ascidians the single nerve ganglion is situated 

 near the anterior end of the body, and between the branchial 

 and atrial apertures. In species where the atrial aperture is near 

 or at the posterior end of the body, the ganglion may also be 

 placed far back, but it still lies between the two apertures and 

 always indicates the dorsal side of the branchial. The ganglion 

 is usually elongated, and gives off nerves at both ends — one set 

 anteriorly arrd ventrally towards the branchial aperture, the other 

 set posteriorly and dorsally towards the atrial. In close relation 

 with the ganglion are found two organs — the neural gland and 

 the dorsal tubercle — which have been much written about, but 

 apparently will bear a good deal of further investigation. 



The neural gland lies upon the ventral and posterior face of the 

 nerve ganglion, and consists of a number of more or less ramified 

 caecal tubules springing from a central space or tube immediately 

 below the ganglion. The presence of this organ was first dis- 

 tinctly pointed out by Albany Hancock in 1868, 2 but until ([trite 

 recently its function was not only totally unknown, but had been 

 scarcely investigated. 



The dorsal tubercle was described by Savigny in 1816 s under 

 the name of " tubercule anterieur." Since then it has received 

 many names, but has usually been regarded as some sort of ol- 



1 Abstract of a paper read before the Royal Society of Edinburgh, 

 April 2- 



3 Joum. Linn. Soc. (Zool."), vol. ix. 



3 " Me*moires sur les Animaux sans Vertebres," pt. it. fasc. 1. (Paris, 

 1816.) 



