334 



NA TURE 



[February 6, 1902 



produces a copious secretion of pancreatic juice. This body, 

 which for the present is termed secretin, is associated with an- 

 other body with a pronounced lowering efl'ect on the blood 

 pressure. The two bodies are not identical, since acid extracts 

 of the lower end of the ileum produce the pressure-lowering 

 eftect, but have no excitatory influence on the pancreas. 



Observations indicate that seirelin is probably a body of 

 very definite composition, and of small molecular weight. Dr. 

 Osborne is at present engaged in an investigation of its chemical 

 characters and identity. 



"On the Excretory Organs of Amphioxus." By Edwin S. 

 Goodrich, M.A. , Fellow of Merton College, Oxford. Com- 

 municated by E. Ray Lankester, F. R.S. 



Linnean Society, January l6. — Prof. S. H. Vines, F.R.S., 

 president, in the chair. — iSIr. Alfred O. Walker exhibited some 

 branches of cherry affected with a fungus disease caused by 

 Gnoinonia erythrostoma. — Mr. J. E. Harting exhibited some 

 heads of wild sheep, together with photographs and lantern-slides, 

 to illustrate a recent suggestion as to the use and value of spiral 

 horns in feral species. Dr. George Wherry, of Cambridge, who 

 originated the discussion and was present as a visitor, se- 

 lected Ovis nivicola of Kamtschatka as a typical species to 

 support his theory, and pointed out that while the horns were 

 enormous, the ear was remarkably short, situated exactly in the 

 axis of the spiral, and, as it were, at the apex of a hollow cone 

 formed by the great spiral horn. This he regarded as a provision 

 of Nature to enable the animal to hear better and to determine 

 the direction of sounds when there is a mist or fog, the horn 

 acting like an Admiralty megaphone when used as an ear-truirpet. 

 Mr. Harting pointed out that the remarkably large spiral horns 

 were peculiar to the male sex, and that if they were to be 

 regarded as of use for the preservation of the species, the ewes, 

 which required the most protection, would be in that respect 

 defenceless. This would be especially the case with Ovis 

 nivicola, the sexes of which, according to Dr. Guillemard 

 (" \'oyage of the Marchesa," vol. i. p. 214), lived apart in small 

 herds for some portion of the year. It was a significant fact, 

 also, that wild sheep, like other wild animals, posted sentries 

 whilst feeding to prevent being surprised by their enemies, and 

 it was the experience of those who hunted them that when 

 approached the alarm was generally given by a ewe. He 

 thought that wild sheep and goats, like deer, relied more upon 

 their sense of sight and smell than upon their hearing, and that 

 the large horns, like those of other ruminants, were simply 

 weapons of defence against wild carnivora, and of offence 

 against rivals during the breeding-season, as in the case of deer. 

 Dr. Wherry, in reply, thought it would be found, in the case 

 of ewes in which the horns were either absent or rudimentary, 

 that the ears, by way of compensation, were much larger than 

 those of the rams ; but he had been unable to find anywhere a 

 head of a female Ovis nivicola for examination. — Messrs. H. and 

 J. Groves read a paper on the use of Linnean specific 

 names. They showed that great diversity of practice existed 

 in dealing with these names, and pointed out the necessity of 

 arriving at some agreement as to their use as a first step towards 

 uniformity in nomenclature. They grouped the Linnean 

 specific names under the following heads: — (i) Those applied 

 to distinct species fairly well understood in Linna-us's time, and 

 still generally accepted. (2) Those which are now considered 

 to include two or more species, combined by Linnreus owing to 

 either (a) the imperfect knowledge of the plants at the time, or 

 (/;) the different ide.is then and now as to the extent of species. 

 (3) Those about which there is more or less doubt as to their 

 proper application, owing to (a) the descriptions being imperfect, 

 (//) the synonymy {often the most important part of the 

 description) being contradictory, or (i) confusion due to changes 

 made by Linn.eus himself after publication. .After discussing 

 the various methods adopted and the difficulties connected with 

 each, Messrs. Groves recommended that in doubtful cases, so 

 far as possible, the description in conjunction with the reference 

 to earlier authors should be relied on, always construing the 

 species liberally, and that when the specimens in the Linnean 

 herbarium or amendments in the second edition of " Species 

 Plantarum" are at variance with this conception of the species, 

 they should be disregarded. As regards group 2, they 

 recommended that the name should be retained for the type if 

 specified, or if not to the species which may be most fairly 

 regarded as the t)pe, and in the absence of such to the residuary 

 species after others had been cutoff; and as regards group 3, 



NO. 1684, VOL. 65J 



that unless the evidence is hopelessly vague, or contradictory, 

 the names should be retained for the species for which the 

 weight of evidence points to ^heir having been intended. 

 Specimens were exhibited of the plants which, following the 

 practice advocated, would stand as Hypericum quadrangulum, 

 L., EpilobiumalpiniiinanAE. tetragonum, L., axiA Sparganium 

 ereclutii, L. , also of the allied species in each case bearing on the 

 question. 



CAMBRIDGE. 

 Philosophical Society, January 20.— Prof. Macalister, 

 president, in the chair. — On the question of "predisposition" 

 and "immunity" in plants, by Prof. H. Marshall Ward, F.R.S. 

 The author directed attention to previous work by himself and 

 others which indicates that plants are not merely passive to the 

 attacks of parasites, and especially referred to experiments with 

 the rust fungi (Uredinea;) which clearly show that not only do 

 these parasites vary and differ in their powers of adaptation to 

 different hosts of the same species or genus, but the hosts exert 

 definite reactions on the fungi. In particular, the results 

 of a large series of infection experiments made by the author 

 with the uredo of Puccinia dispersa, the brown rust of 

 the bromes, were summarised. During the past summer more 

 than 1800 such experimental infections were made on twenty-two 

 varieties and species of Bromus, belonging to four out of the five 

 subgenera. The infecting spores were derived from three 

 different species of Bromus. The results show distinctly that 

 not only does the power of the fungus to attack a given species 

 of the flowering plant depend on the specific nature of the latter, 

 but it also depends on the specific nature of the previous host 

 on which the spores were produced. The conclusion is arrived 

 at that specific predisposition and immunity in plants depend on 

 similar internal mechanisms and conditions to those which de- 

 termine the possibility or otherwise of cross-fertilisation, and 

 just as this possibility varies and may be increased or diminished 

 by inheritance in breeding, so may the capacity of resistance to 

 infection vary and be increased or diminished in different races. 

 It is probable that secretions of enzymes, chemotactic sub- 

 stances, toxins and antitoxins in the cell play a part in all such 

 processes. — On the genito-urinary organs of dipnoan fishes, by 

 Mr. Graham Kerr. — Further observations on the biological test 

 for blood, by Mr. George H. F. Nuttall. The paper refers to 

 studies of what the author terms "blood-relationship" amongst 

 animals by means of test-tube reactions with various anti-sera. 

 The results of the investigation of .some 440 species of blood go 

 to show that the biological test for blood may possess considerable 

 value in relation to zoological study. 



Manchester. 

 Literary and Philosophical Society, January 21. — 

 Mr. Charles Bailey, president, in the chair. — Mr. W. E. Iloyle 

 made some remarks on a case of failure of concrete flooring 

 strengthened by steel bands. — .\ paper, entitled "On Xetwphyton 

 radictilosum (Hick), and on a stigmarian rootlet probably related 

 to Lepidopliioios fuliginosus (Williamson)," was read by Prof. 

 F. E. Weiss. He gave his reasons for regarding the fossil 

 Xenophyton, described by the late Thomas Hick in 1891, as a 

 stigmarian " root " or rhizome, which, on account of the peculiar 

 structure of its vascular cylinder and of its massive and well- 

 preserved middle cortex, he considered to be closely allied to 

 the lepidodendroid stem known as Lepidopliioios fuliginosus. 

 lie also described a stigmarian rootlet, which he considered to 

 be related to Lepidophloios. This rootlet was further remark- 

 able on account of the presence, in its well-preserved cortex, of 

 a vascular branch similar to that described for stigmarian root- 

 lets of a different type by Renault. Prof. Weiss stated that he 

 had been able to confirm the occurrence of such branches from 

 the central cylinder in several other stigmarian rootlets, in the 

 collection of the Manchester Museum. 



EDINBt'ROH. 

 Royal Society, December 16, 1901. — Prof. Geikie in the 

 chair. — Dr. T. J. Jehu read a paper on a bathymetrical and 

 geological study of the lakes of Snowdonia and eastern 

 Carnarvonshire. It was clearly demonstrated that ice action 

 had been an important factor in the formation of many of the 

 valleys and lakes of the district, although at the same time it 

 was also evident that other geological agents had been at work. 

 The comparatively great depth of certain of the lakes, of which 



