Societies and Academies

Abstract

LONDON Linnean Society, March 16.—Sir John Lubbock, Bart., M.P., F.R.S., president, in the chair.—Messrs. H. M. Brewer, V. I. Chamberlain, and A. P. Withiel Thomas were elected Fellows of the Society.—Mr. J. Worthington Smith called attention to certain very destructive Australian fungi new to England, viz. Capnodmm australe, fatal to conifers, especially Thuyas and Isaria fuciformis, a great pest to grass in Kent and Sussex. The latter plant is popularly supposed to induce a disease similar to diphtheria, and said to be fatal to cattle. Isaria frequently grows on animal substances, dead and living, as on larvæ and pupæ of ichneumons, spiders, moths, wasps, &c.—Mr. Smith showed a bee caught alive in this country, and having a profuse growth of the Isaria-condition ef the Cordiceps sphecocephala, a West Indian form, the latter genus being closely allied to Claviceps, or Ergot.—Dr. Francis Day read a paper upon the Salmones found in the British Isles, remarking how great changes are occasioned by retaining any of them in unsuitable localities. He objected to the augmentation in number of the British forms of migratory trout, from three to seven, as made by Dr. Günther, holding that we merely possess two, The Lochleven trour, which is in reality a marine form, acclimatized to fresh water, whereas the remainder are solely trout races of the common brook trout.—A most interesting fact was brought forward, viz. that Mr. Arthur, in New Zealand, having lately examined the trout which were introduced there in 1869 from ova originally obtained from the Thames and the west of England, found great structural changes had taken place. The fish in question, moreover, living in different streams in New Zealand had also assumed local peculiarities of size and change of form; and, doubtless due to increased food, the annual increment of weight had risen from 11/2 to 21/2 pounds, and an example had been seen weighing 20 pounds. The cœcal appendages hitherto held as significant of species were found augmented from 33 to 50, as exemplified in British fish, to from 43 to 54 in the New Zealand examples, therefore showing that these organs are inconstant as to number. Having alluded to the different species, Dr. Day concluded that, as the various species of non-migratory trout, accepted by Dr. Günther, interbreed, and the results classed hybrids are not sterile, such gives increased reason for supposing these various forms are local races, and not different species; that if they are really distinct species division has not proceeded sufficiently far, because tha Gillaroo, or form of trout with a thickened middle coat of the stomach, has been termed Salmo stomachicus, Günther, whereas the great lake trout with a ihickened stomach, and the Charr having a similarly transformed organ, have not yet been differentiated into species. Dr. Day considers that all our non-migratory freshwater trout (including the Loch Leven) are merely local races; that interbreeding will produce mongrels, in which sterility need not be anticipated, while introducing new races (unless in the principle of preventing breeding in and in) will not be of much benefit to fisheries, unless the food is in excess of local requirements, for if not the new-comers will revert to the colour, form, and size of the original tenants of the water.—Two papers by Mr. Charles Darwin—(1) on the action of carbonate of ammonia on the roots of certain plants; and (2) the influence of carbonate of ammonia on chlorophyll bodies were read, abstracts of which appeared in last weeks NATURE.—The twelfth part of the Rev. A. Boog Watson's contributions to the mollusca of the Challenger Expedition was also read.