October 20, 1904] 



NA TURE 



601 



during the past year is a real help lo the astronomical 

 investigator, and saves him much time and labour. In 

 spile of the mass of material that is embodied in the 

 work, the volume is, according to pages, onlj- a trifle 

 larger than its immediate predecessor, and somewhat 

 smaller than vol. iii. .\s a matter of interest, it may 

 be stated that the number of references in the present 

 and the two preceding volumes are 2582 for vol. v., 

 J411 for vol. iv., and 2513 for vol. iii. 



In conclusion, the statement made with regard to 

 the earlier volumes, namely, that they should be found 

 in every astronomical library and observatory, may be 

 repeated in the present case. W. J. S. L. 



LETTERS TO THE EDITOR. 

 \Tlie Editor does twt hold himself responsible for opinions 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



The Foiest-pig of Central Africa. 



I ii.vvE spcn Mr. Oldfield Thomas's interesting letter in 

 your issue of October 13 relative lo the remarkable forest- 

 pig (which he has named Hylochocrus meincrtzliageni). 

 With regard to the discovery of this remarkable beast, there 

 are perhaps other names which should be associated with 

 it as well as those of the late Sir Henry M. Stanley and 

 myself. No ineniion of this forest-pig appears in .Sir Henry 

 Stanley's published works, but in lonversalion with myself 

 and others he frequently told us that, in addition to hearing 

 of a " donkey-like animal with large ears " (which after- 

 wards turned out to be the okapi), he once saw a huge 

 black pig, .ind he had reason to believe that a strange new 

 species or genus of pig inhabited that portion of the Congo 

 Forest near the Semliki River. I heard and transmitted 

 similar stories told me by the natives of that forest ; but 

 even more detailed accounts were collected and sent later 

 on by the late W. G. Doggett, who, to the great loss of 

 zoological collecting in Africa, wds d''owned in the River 

 Kagera in the early part of the present year. But I think 

 the first definite accounts of this pig (or at any rate of 

 Ilylochoerus mcinertzhageni) were transmitted by Mr. 

 t". W. Hobley, C.M.G., a sub-commissioner of the East 

 .\frica Protectorate, who has recently been acting as Com- 

 missioner after the departure of Sir Charles Eliol. Mr. 

 Hobley sent a drawing of the skull and a description of 

 the creature from imperfect specimens he had seen on the 

 slopes of Mount Kenia. Unfortunately his letters were 

 delayed in transmission, so far as their reaching the 

 Zoological Society was concerned. Mr. Hobley is now in 

 ICngland, and it is to be hoped that he will furnish the 

 Zoological Society in detail with the extremely interesting 

 particulars he has given me in conversation regarding this 

 remarkable animal. I would remind your readers that Mr. 

 Hobley (who as regards length of service is almost the 

 senior British ofilicial connected with British East Africa) 

 made the important discovery last year of marine organisms 

 in the Victoria Nyanza. 



So far, the native stories of the okapi and the big forest- 

 pig have turned out to be true. It only remains to complete 

 the trilogy by the discovery of a third mysterious animal, 

 also alluded to in conversation, if not in writing, by Stanlev, 

 and mentioned by Doggett and myself. This, so far as 

 native accounts can be crystallised into a definition, would 

 seem to be some large tragelaphine antelope resembling 

 the nilghai in appearance, with short, twisted horns. A 

 horn or a pair of horns attributed to this animal was, I 

 believe, brought home by a member of Stanley's e.xpedition, 

 and is possibly in the British Museum. It was seen by 

 Dr. P. L. Sclater, and attributed by him to an abnormallv 

 developed cow eland ; but so far as I could learn from my 

 own researches and those of JDoggett, the natives of the 

 Semliki Forest were careful to differentiate this creature 

 from either the forest eland or the bongo. Their accounts 

 of it certainly coincide to a great e.xtent with their stories 

 of the okapi, though they insisted on the difference between 



NO. 1825. VOL 70] 



the two animals. Perhaps there is as much truth in their 

 stories of this large antelope with small twisted horns as 

 there has been shown to be in connection with the okapi 

 and the forest-pig. H. H. Joiixsios. 



Mendel's Law: a Crucial Experiment. 



I SEE from the published account of a recent discussion 

 at the Cambridge meeting of the British .\ssociation that 

 the facts of Mendelian segregation are still disputed by the 

 biometric school of evolutionists. I venture, therefore, to 

 submit to your readers the result of an experiment carried 

 out at the Royal Botanic Gardens, Peradeniya, which, in 

 my opinion, proves conclusively that in a particular cross- 

 bred form a particular pair of characters did become segre- 

 gated in equal numbers of germ cells, both male and female. 

 'J'he characters in question were ; — the appearance and 

 absence respectively of a yellow coloration in the endosperm 

 of grains of Indian corn {Zea Mays). These characters are 

 discontinuous in the strain examined. Among about 

 100,000 grains which passed under my notice, I saw only 

 two which were partly yellow and partly white ; these were 

 counted as yellow, being presumably heterozvgotes. 



Some of my specimens were exhibited by Mr. Bateson at 

 the recent meeting of the British Association, but I can now 

 add the results of a further generation. 



The facts are represented in the following scheme, in 

 which the absence of the yellow pigment is expressed by 

 the term ' white." 



f(i) White flint corn :1 ('{2) Yello 



I. • extracted reeessive - 9 ^ s] ofthes 

 I from a mongrel strain 



flint corn ;1 

 . -. 1..^ same mongrel 

 (^ strain as (i) J 



II. 



fi^) Yellow 1 

 \ grains / 



^ . /(4) Offspring of (i) ;\ 

 I (_ self-pollinated white/ 



III. (5) 1963 yellow (4976 per cent.) + (6) 19S2 while. 



The plants arising from these grains, both white and 

 yellow, were used as seed parents in the next generation, 

 ihe pollen parent being " Boone County White " dent corn. 

 There resulted : — (a) Offspring of white grains — some 30,000 

 white grains and 27 yellow grains (009 per cent.) ; the latter 

 were accounted for by the escape of " yellow " pollen. 

 (6) Offspring of yellow grains — generation iv. : — 



IV. 26,792 yellow (50"03 per cent.) + 26,751 white. 



/ Self. \ 

 \^ pollinated y 



V. 16,582 yellow + 5681 white (25-5 per cent.) 



The plants arising from the above yellow grains (gener- 

 ation iv.) were also used as pollen parents for a cross in 

 which the seed parents were the offspring of " Boone County 

 White " crossed with a strain of extracted recessives from 

 the original mongrel flint corn. There resulted : — 



2507 yellow (492 per cent.) -|- 2503 white. 



I would direct particular attention to the following 

 points ; — 



(i) That a perfect Mendelian result was obtained among 

 the offspring of an impure race. 



(2) Lest it should be objected that possibly the ancestry 

 of this mongrel strain included equal numbers of yellow 

 and white individuals, a pure recessive strain (" Boone 

 County White," imported from U.S.A.) was introduced into 

 the pedigree, so that the next generation (iv.) possessed at 

 least three times as many white ancestors as yellow. On 

 self-pollinating the offspring of yellow grains, the Mendelian 

 proportion 3 yellow to i white was obtained. 



(3) In two generations the female germ cells borne upon 

 the heterozygotes were tested by crossing with the recessive 

 form. In each case half of the germ cells were found to 



