September 19, 1912] 



NATURE 



71 



the possible mixing up of the relics, but the excava- 

 tions have been closely watched and studied by myself 

 and several fellow-members of the local Archaeological 

 Society, and if there is one point clearer than another 

 it is that there has been no such disturbance. The 

 tree stumps in the overlying forest bed are as they 

 grew, with their roots passing into the underlying 

 strata, and everything indicates quiescence. Nor 

 could the objects have sunk through the peat, for of 

 the abundant stones in the overlying deposits, none 

 have even penetrated the surface ; the material is too 

 compact to admit of this. 



These interesting relics now form part of the exten- 

 sive and ever-growing collection in the museum of 

 the local .A.rchseological and Antiquarian Society, the 

 Soci^t^ Jersiaise. 



It would be interesting to know if any of your 

 numerous archaeological readers have found evidences 

 of Neolithic man at this geological horizon. 



Jersey, August 28. J. Sinel. 



The Structure of the Ciliary and Iris Muscles in Birds. 



May I be allowed through your columns to direct 

 the attention of physiologists and anatomists to certain 

 special features in ocular accommodation, and in the 

 movements of the iris in birds, and to a peculiarity 

 of the ciliary muscle and sphincter of the pupil, wliich, 

 so far as I have been able to ascertain, has not been 

 previously described? 



If the eye of any bird in which a light-coloured iris 

 sharply contrasts with a black pupil be carefully 

 watched, rapid changes in the size of the pupillary 

 opening may be sometimes observed to take place 

 during the few moments that the bird is fixedly look- 

 ing at any object under the same intensity of illumina- 

 tion. Moreover, the character of these movements 

 strongly suggests that they are under voluntary 

 control. 



The pupillary reaction to light is very rapid in birds ; 

 the recontraction following the transient dilation 

 which accompanies the momentary closing and open- 

 ing of the eyelids and nictitating membrane in the 

 movement of blinking is so rapid that the contraction 

 of the pupil seems to coincide with the re-opening of 

 the eye, and not definitely to follow it as in man. 



Atropine seems to have no effect in dilating, or 

 Eserin in contracting, the pupil ; neither does the 

 former seem to affect accommodation in birds. 



In connection with these facts it is also interesting 

 to find that the ciliary muscle and the sphincter of 

 the pupil in birds are both composed of striated fibres 

 of the voluntarv type, and not of plain unstriped 

 muscle fibres as in man and other animals. 



Thus, while in man with binocular vision the deli- 

 cate movements of accommodation and the associated 

 movements of the pupil are carried out by involuntary 

 muscles, in birds, in which in many species vision is 

 of the monocular type, the same movements are per- 

 formed by voluntary muscles. 



The extremelv accurate and rapid movements of 

 the beak in birds no doubt require a corresponding 

 delicacy and rapidity of ocular accommodation at very 

 short range. 



Other interesting questions arise as to the repre- 

 sentation of these intrinsic eye movements in 

 the avian brain. The matter is also one of phylo- 

 genetic interest, and I hope to publish further histo- 

 logical details with photomicrographs of sections 

 shortly. C. J. Bond. 



Leicester, August 30. 



that his hypothesis may be tested by careful observa- 

 tion in many parts of the world. As regards the 

 rarity with which these attacks have been wit- 

 nessed in India by Mr. Evershed and many other 

 naturalists, it is well to bear in mind the probability 

 that the proportion of butterfly-eating birds differs in 

 the different tropical regions. Indeed, it is difficult 

 on any other hypothesis to understand why butterfly 

 mimicry should be developed to such very different 

 degrees in the three richest regions, being transcendent 

 in the Neotropical, remarkable in the Ethiopian, but 

 relatively poor in the Oriental region. Indirect evi- 

 dence of the frequency of attacks in different areas 

 might perhaps be obtained by a study of the relative 

 amount of damage which could only have been in- 

 flicted by the beak of a bird. E. B. Poulton. 

 St. Helens, Isle of Wight, August 26. 



The Attacks of Birds upon Butterflies. 



Mr. Evershed's letter in Nature of .August 20 

 seems to me very suggestive, and it is to be hoped 



NO. 2238, VOL. 90] 



A Flower-sanctuary. 



In reply to Sir Edward Fry's inquiry (Nature, 

 August 29, p. 661) as to the powers of county councils 

 to protect particular flowers, I am now enabled, 

 through the courtesy of the clerk to the Cornwall 

 County Council, to send a copy of the by-law referred 

 to; it is given below. It is obvious that the Somerset 

 County Council must possess the same powers as the 

 Cornwall County Council, and that a by-law on these 

 lines would meet the requirements of the case, and I 

 venture to hope that Sir Edward Fry will exert his 

 influence in favour of the enactment of such a by-law. 

 Frank H. Perrvcoste. 



Higher Shute Cottage, Polperro, Cornwall, 

 September 12. 



County oj Cornwall. — By-law for the Good Rule 

 and Government of the Administrative County of 

 Cornwall, made in pursuance of the Local Government 

 Act, 1888, by the County Council of the said County, 

 at a meeting held at Truro, on the 6th day of Novem- 

 ber, 1906, at which not less than two-thirds of the 

 whole number of the Council were present : — 



"No person shall (unless authorised by the owner 

 or occupier, if any, or by law so to do) uproot or 

 destroy any Ferns or other Wild Plants growing in 

 any road, lane, roadside, waste, wayside bank or 

 hedge, common, or other public place, in such a 

 manner or in such quantities, as to damage or dis- 

 figure anv such road, lane, roadside waste, wayside 

 bank, or hedge, common or other public place. Pro- 

 vided that this by-law shall not apply to persons 

 collecting specimens in small quantities for private or 

 scientific use. 



"Any person offending against this by-law shall be 

 liable to a penalty not exceeding five pounds." 



THE SUMMER OF 1912. 



THE summer of 191 2 has proved so thoroughly 

 unsummerlike, and has been so marked a 

 contrast to the abnormally fine and hot summer of 

 191 1, that a few facts may be of interest. The 

 period dealt with will be limited to the three 

 months June, July, and August. 



The drought experienced in April, followed by 

 a general deficiency of rain in May, rendered the 

 early summer rains in June agreeable rather than 

 otherwise, but the wet weather soon became too 

 persistent, and the frequent rains have been a 

 special feature of the past summer. With the 

 exception of a period of eight days, July 10 to 17, 

 the weather throughout was unusually cold, and 

 this was really the only dry period experienced 

 over the countrv generallv. 



