6.^,o 



NA TURE 



[October 26, 1905 



the Chelifer is or is not a parasite on the house-fly. It 

 is fully recognised now that house-flies play an important 

 part in the distribution of the germs of certain diseases 

 that affect mankind. Any animal, therefore, that injures 

 or destroys the flies may assist in checking the spread of 

 disease. But if, as Mr. Pocock suggests, the object of the 

 Chelifer is to feed upon the acarine parasites of its host, it 

 serves rather as a friend than a foe to the fly, and should 

 certainly not be called a parasite. 



There is no anatomical reason for believing that the 

 Chelifers that have been found on flying insects are 

 specially adapted to a parasitic mode of life, nor is there 

 any evidence that the house-flies they are attached to aie 

 infested with mites or any other skin parasites. If the 

 Chelifers are not parasitic on the flies, and there are no 

 mites for them to attack, how can the association of the 

 two forms be accounted for otherwise than by the transport- 

 ation hypothesis? 



Since I wrote my last letter to you I have found that 

 this matter has been most fully discussed by Mr. Kew in 

 his article on Lincolnshire Pseudoscorpions in the Naturnlist 

 for July, 1901, and I would refer readers of Nature who 

 are interested in the subject to that paper for fuller par- 

 ticulars. Sydney J. Hickson. 



University of Manchester, October 21. 



The Rudimentary Hind Limbs of the Boine Snakes. 

 It is a well known fact that the pythons and boas and 

 some allied forms among snakes possess rudiments of hind 

 limbs, these vestiges — to quote Boulenger's " Catalogue 

 of Snakes in the British Museum " — " usually terminating 

 in a claw-like spur visible on each side of the vent." 

 These structures are always mentioned in general works 

 upon Ophidia, such as Hoffmann's account of the serpents 

 in vol. vi. of Bronn's " Klassen und Ordnungen des 

 Thierreichs," and Gadow's " Reptiles and .\mphibians " in 

 the " Cambridge Natural History." But in none of the 

 three treatises to which I refer is there any further account 

 of the " claws " or " spurs." It is merely stated that thev 

 are present. It is not mentioned in these works, nor in 

 some others which I have consulted, that the claws in 

 question offer valuable sexual characters by the aid of 

 which individuals can be referred to their proper se.K, at 

 least in certain Boidse. The fact that these characters 

 have been so largely overlooked is perhaps due to the 

 slight stress laid upon them by DumcJril and Bibron 

 {Erpitologie Generale, vol. vi., 1844), who, however, did 

 direct attention to the occurrence of differences in these 

 organs between the two sexes in a number of Boidie. But 

 they speak of the claws merely as being " d'une tr^s petite 

 dimension chez des femelles," and as " plus d^velopp^s 

 chez les males que chez les femelles." The first of these 

 quotations refers to Eunectes, the second to Boa. The 

 differences, however, in Eunectes notaetis are greater. In 

 this southern anaconda, of which several specimens were 

 lately deposited in these gardens by the Hon. Walter 

 Rothschild, there is in the male a' sharp curved claw 

 turned downwards and ridged along its lower surface. In 

 the female, on the other hand, the representative of this 

 claw is not a claw at all strictly speaking— if, that is to 

 say, we mean by a claw a nail-like structure which is 

 curved and compressed and ends in a sharp point. In the 

 female there is a straight, blunt, horny process distinctly 

 unlike the sharp claw of the male. In two young example's 

 of this anaconda, which are females, the same type of 

 horny structure is found as in the adult female. In the 

 allied genus Eryx there are still greater differences between 

 the two sexes. Frank E. Beddard. 



Zoological Society's Gardens, October iS. 



A Rare Game Bird. 



Mr. Sawbridge (p. 605) has raised one of the most per- 

 plexmg points connected with bird-migration. I cannot 

 answer for the eastern counties of England, but here in 

 the south-west of Scotland, we are still further from 'the 

 headquarters of the quail than he is. Fiftv vears a^o 

 quails bred regularly in western Galloway ; 'as' a bov^I 

 recollect that two or three brace were quite a common 

 complement to a September bag. Indeed, when a 

 NO. 1878, VOL. 72] 



" cheeper " or undersized partridge was shot, " Put it 

 down as a quail! " was the usual comment. These birds 

 gradually disappeared ; the last that I myself shot was 

 about the year 1868 ; but an odd one has been obtained 

 here and there in the district ever since. One, I know, 

 was shot last month in the neighbourhood of Newton 

 Stewart, and was reckoned such a curiosity that it was 

 sent to the bird-stuffer. I am sorry that I do not know 

 whether it was a young or an old bird. Besides this, other 

 instances, if I mistake not, have been recorded in the 

 Field from different parts of the country. 



As to the cause of the general disappearance of quails 

 from this district, there have been many speculations, the 

 commonest notion being that the supply is so heavily taxed 

 in the Mediterranean region that few birds escape to the 

 north. Truly, when one considers the enormous consign- 

 ments of quails to London, Paris, &-c., there is no reason 

 for surprise that the migrants should dwindle in number. 



I have a vague recollection of being told in boyhood 

 that about the year 1838 there was a large influx of quails 

 into Galloway, and that they had bred there ever since, but 

 in numbers annually decreasing. It is conceivable that a 

 storm-driven flock may have been carried out of their 

 bearings, and, finding food abundant and climate endurable, 

 if not altogether congenial, remained as colonists, but 

 that our wet summers have proved adverse to their voung 

 being reared. The fluctuation in the stock of partridges 

 caused by the character of different seasons is very remark- 

 able, and evidently neither the numbers nor the constitution 

 of our quails have enabled them to survive adverse con- 

 ditions of temperature and rainfall. This makes the 

 sporadic occurrence of individuals at long intervals all the 

 more remarkable and perplexing. 



Herbert Maxwell. 



Monreith, Wigtownshire, October 22. 



On a New Species of Guenon from the Cameroons. 



A CHARMINGLY docile species of guenon, obtained bv 

 Cross, of Liverpool, from the Cameroons, in West .Africa, 

 and recently submitted to me for identification proves to 

 be undescribed. I propose for it the name Cercopiihecus 

 crossi, in compliment to the courteous proprietor of 

 that large and well known importing house of wild 

 animals, and for popular use the same of Cross's 

 guenon. The animal is a male, apparently nearly full 

 grown, but not entirely adult, as the condition of its 

 teeth indicate. It is very similar to C. moloneyi of 

 Sclater, in general appearance, in having the broad rufous 

 lower back, but differs in having a large and bushy pure 

 white beard, white throat, and bushy whiskers of' black 

 hairs ringed with white ; the band across the forehead deep 

 black instead of fulvous ; sides of head speckled black 

 and white ; underside of body sooty-black speckled with 

 white ; the tail not deep black except at tip, but speckled 

 black and white like the upper part of the back ; the 

 black on the forearm externally does not extend to the 

 shoulder, and not much beyond the elbow ; the outer aspect 

 of thighs is black slightly peppered with white ; the inside 

 of arms below the elbow black, higher up sooty-grey ; 

 inside of hind limbs sooty-black. 



The top of the head is black, the hairs sparsely ringed 

 with white; the face, cheeks, and ears quite nude and 

 purplish black in colour ; long superciliary hairs are 

 present ; the callosities are small and purplish sooty-grev 

 in colour. 



From C. albigularis (Sykes's guenon) the present species 

 differs in wanting the yellowish wash on shoulders, fore 

 and hind limbs, and in having a brindled and not a black 

 t^il- Henry O. Forbes. 



The Museums, Liverpool, October 12. 



The Absorption Spectrum of Benzene in the Ultra-violet 

 Region. 

 We were glad to see in Nature of October 5 a letter 

 from Prof. Hartley in which he points out the near agree- 

 ment between our measurements of the bands in the 

 absorption spectrum of benzene and those made by Prof. 

 Dobbie and himself. He also directs attention 'to the 

 work of Friederlchs, who, in the case of benzene vapour, 



