September, 1911 



KNOWLEDGE. 



355 



The cyst at first contains a centrally-placed nucleus, with a 

 karyosome. Inside some of the cysts division occurs, and 

 eight daughter forms .are produced. 



The author tried the effect on Entamoeba colt of 

 '■ auxetics," substances such as tyrosin and leucin, occurring 

 naturally in the human body and capable of inducing division 

 in living cells. The substances are best used in a jelly with 

 agar, sodiuni chloride and an alkali (sodium bicarbonate), 

 forming a slightly alkaline culture medium. When such a 

 medium containing about 0-2 per cent, of tyrosin is inoculated 

 with cysts of Etitaniocba coli, the period of the life-cycle is 

 shortened and the amoebae in the culture reproduce for 

 several generations. The author mentions a culture which 

 had gone through five generations. One interesting and novel 

 result on tyrosin-containing media is that a complete life- 

 cycle of Entamoeba coli is passed through in about three 

 days (at 20' to 25" C.l, when all the amoebae of a given 

 generation have encysted. Then a large number of the cysts 

 produce eight daughter forms inside them, and the amoebulae 

 come out of the cysts and start a new generation in the same 

 medium. The process of binary fission which also frequently 

 occurs in such media involves a primitive mitosis (or 

 promitosis! of the nucleus, caps of chromatin derived from 

 the karyosome being formed at the ends of the rudimentary 

 spindle. 



The subject of this research, Entamoeba coli, is usually 

 considered to be non-pathogenic : it lives in the lumen of the 

 large intestine and on the contents thereof; it is incapable of 

 penetrating the mucosa. The size is slightly variable from 

 12 to 25 ," in diameter. 



G. Plant Deelev. 



ORNITHOLOCxY. 



By Hugh Boyd Watt, M.B.O.U. 



A NEW BRITISH BIRD — THE ALPINE RING- 

 OUZEL. — The occurrence of this form of the Ring-Ouzel 

 (Tiirdiis torqiiatiis alpestris) is recorded for the first time 

 in Great Britain by Mr. M. J. Nicoll, in British Bints (V, 

 August. 1911. pages 72-73), on the strength of an adult male 

 shot at Guestling, Sussex, on 23rd May, 1911. The illustration 

 given shows the form to be generally whiter in appearance 

 than the common Ring-Ouzel. The Alpine bird has a wide 

 range, extending in the breeding season throughout middle and 

 south Europe to the Balkans, 



THE IRISH COAL-TITMOUSE— (P.4/^t'.S HIBER- 

 XICUS). — In the current number of The Ibis (9th Series 

 V, July, 1911, pages 54,S-552), Mr. W. R. Ogilvie-Grant gives 

 what may be taken to be a definite finding on this bird (see 

 ''Knowledge" for March, 1911), He modifies his earlier 

 claim for its full specific rank, and, as the British Coal-Titmouse 

 also occurs in Ireland, and the two forms to some extent 

 intergrade, he now regards the Irish bird (P. hiberniciis) as a 

 sub-species only, though a very distinct one. 



Mr. Ogilvie-Grant makes the suggestion that some characters 

 of the Irish bird indicate that its origin is much more ancient 

 than its British representative, and that it is a pre-glacial type 

 which has survived in the western and southern parts of 

 Ireland. He points out that the form most closely allied to 

 the Irish bird is, in many respects, another Coal-Titmouse 

 iPanis ledoucii Malh.,) peculiar to Algeria and that the 

 Lusitanian element in the fauna of Ireland is illustrated by 

 this. He remarks that the distribution of the Strawberry tree 

 (Arbutus unedo'i, which has a wide range in the Mediterranean 

 region and is found in the neighbourhood of Killarney as well 

 as in Algeria, is most interesting, as bearing on the question of 

 the Irish and .Algerian Titmice, \\'hat bearing the interest 

 exactly has on the case of the Irish Coal-Titmouse is not 

 stated, 



GROUSE AND DISEASE. — " No disease" is the 

 prevailing report from grouse moors this season, and in 



addition to the healthy state of the birds their numbers in 

 Scotland are believed to be greater than in any past year. 

 This exceptionally good season coincides with the publication 

 of the elaborate report of the Committee on Grouse Disease, 

 the result of some six years investigations, under the Chair- 

 manship of Lord Lovat, the general (juestions being treated 

 bv Mr. X. S. Leslie and Dr. E. A. Wilson and the scientific bv 

 Dr. A. E. Shipley. 



According to the experts, who have gone into the whole 

 matter with a thoroughness that entitles them to utter the last 

 authoritative word on the subject, the one disease among grouse 

 that spreads havoc and desolation among the birds is caused 

 by what Lord Lovat — turning the expert's highly technical 

 nomenclature into the plainest possible language — terms an 

 over-infection of the Strongyle worm — a worm that is found in 

 practically every grouse on a moor ; that is to say (to quote 

 Lord Lovat), "that almost every bird (grouse) contains in its 

 body, under normal conditions, the immediate caiise of 

 " grouse disease," and is to a greater or less extent an agent 

 for the dissemination of that scourge." This means that the 

 Strongyle worm will be found to-da\- in practically e%'ery one 

 of the unusually numerous and healthy grouse on practically 

 every moor in Scotland. And the Strongyle worm has always 

 been there, but where and w^hen the grouse — so to speak — are 

 stronger than the worm there is no " disease." The " disease" 

 breaks out when and where the worm is stronger — so to speak 

 — than the bird, although of course the strength of the worm 

 has nothing to do with its name. It follows, therefore, that in 

 the present year, with grouse so healthy everywhere, the con- 

 ditions must have been such that the birds have been able 

 to keep their worms under proper check, and if that be so it is 

 e\ident that to those in any way skilled in moorcraft — with the 

 Committee's two sumptuous volumes in their hands, and by a 

 study of the conditions — there should now be little difficulty in 

 so managing grounds and grouse alike that the largest possible 

 stocks of the healthiest possible birds should be the result. — 

 The Glasgo-u' Herald. 12th August, 1911. 



There is every likelihood that the sport will be so managed 

 during the present season that 1912 should prove as healthy a 

 grouse year as 1911 — if the w-eather also help as it has 

 undoubtedly done during this and last year. .According to 

 Lord Lovat, in his admirable chapter on moor management in 

 the Committee's final report, " the immediate objective of the 

 moor owner (who wants good stocks of healthy grouse) stands 

 out clearly — to keep the Strongyle infection at its lowest, to 

 keep the power of resistance of the stock at its highest, and at 

 the same time to maintain the greatest number of birds that 

 the moor is capable of supplying with suitable food." To 

 put it briefly and in practical language, his Lordship suras up 

 the whole matter in these further words — " Moor management 

 is the science of distributing the stock of birds over the moor 

 so that at no period of the year can any area be so infected by 

 the Strongyle worm as to make it a source of danger to the 

 least well-nourished bird on that area," 



MARKING BIRDS AND MIGRATION.— There are 



some reasons for looking with dubiety on the v.arious bird- 

 marking schemes now in operation. Their partial and limited 

 scope, and the danger of making general deductions from the 

 meagre returns obtained, are fair points for consideration, and 

 also the destruction of bird-life which may be entailed in pro- 

 curing these returns, although such destruction is not approved 

 of by the inquirers. Those who share such apprehensions are 

 recommended to study Mr. A. Landsborough Thomson's recent 

 paper on "The Possibilities of Bird-Marking, with special 

 reference to the Aberdeen University Bird-Migration Inquiry" 

 (Proceedings Royal Physical Society, Edinburgh, XVTII, 

 3, 1911, pages 204-218), which gives, in admirable terms, a well- 

 considered and reasoned statement of the subject, .Apart 

 from general and historical and other results, of which a good 

 and valuable account is given, covering Great Britain, the 

 Continent and the U,S..A., the paper tells of the particular 

 investigation now in hand at Aberdeen, This has the advan- 

 tage of being a piece of research work organised under a 

 responsible body, viz,, the Natural History Department of the 



