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HARD WICKE'S SCIENCE- G OSS IP. 



as Sweden, their line of flight is still more easterly 

 than that of the white stork ; even Holland being very 

 rarely visited by them."— H. W. Lett, M.A. 



Red-throated Diver in Cambridgeshire. — 

 Two specimens of this bird were captured in this 

 county last November. I am not sure as to the 

 exact locality, but I think it was Isleham fen. — Albert 

 H. Waters, B.A., Cambridge. 



The Skua Gull. — A specimen of this bird was 

 also taken in the Cambridgeshire fens about the same 

 date [November, 1882].— Albert H. Waters, B.A., 

 Cambridge, 



Prussic Acid in Myriopods.— Many vegetable 

 substances have recently been found also to be 

 secreted by animals, such as cellulose, chlorophyll, 

 and even starch in certain Planarians. Now we hear 

 from Holland of a peculiar species of Myriopod found 

 in greenhouses, which gave out a strong smell of 

 bitter almonds, and from which, by distilling a few 

 specimens with water, prussic acid was actually 

 obtained. 



Embryogeny of the Bryozoa.— Dr. Jules Barrois 

 thinks the Entoprocta should be regarded as the 

 original type of the "sea-mats," and that we may 

 conceive of the original formation of a bryozoan at 

 the expense of its larva as resulting from a simple 

 change of life in a creature resembling a rotifer. He 

 concludes that our "sea-mats" may have been 

 derived originally from free-swimming creatures ana- 

 logous to rotifers. 



Water-Snails.— The author of the articles upon 

 this subject, which appeared in the last volume of 

 Science-Gossip, writes to us as follows :— In reply 

 to Mr. B. B. Woodward's friendly criticism of my 

 paper, I fear I must plead guilty to the charge of 

 having repeated an old and exploded statement of the 

 formation of shells. Curiously enough Mr. Wood- 

 ward himself seems to have only recently formed a 

 decided opinion upon the subject, for a friend calls 

 my attention to "Science for All," 18S0, wherein 

 Mr. Woodward thus expresses himself: " Each layer 

 of the shell was really, some maintain, once a portion 

 of the mantle itself, which became calcified, that is, 

 hardened with carbonate of lime, and was then thrown 

 off to unite with those previously formed. Professor 

 Huxley, however, believes that shell-growth is not a 

 case of conversion, but one of excretion, and that the 

 shell is built up of successive excretions of membra- 

 nous laminre, in which granules of carbonate of lime 

 are deposited. . . . Whichever theory be adopted, the 

 result remains the same." With reference to the 

 other point I must take shelter behind my authority. 

 In the " Quarterly Journal of Microscopical Science" 

 for October, 1S74, Professor E. Ray Lankester de- 

 scribed a series of minute and careful observations on 

 the embryonic development of Limncea slagnalis. In 



this article, which should be seen by all interested in 

 the subject, he states " the foot is essentially a greatly 

 developed lower lip " (page 367). This was my 

 authority, but in a paper which distinctly aimed at 

 being popular, and creating an interest in the subject, 

 names and references were purposely excluded. For 

 the same reason a detailed statement of the homology 

 of the "foot " in gasteropoda would have been out of 

 place, had my knowledge of comparative anatomy 

 allowed me to give it. 



Capture of Apollo Butterfly in Devon- 

 shire. — In reply to Mr. W. J. V. Vandenbergh, I am 

 happy to give all the information I can regarding my 

 lucky capture. I forget the exact date, but it was 

 towards the end of summer, I think in August, about 

 three years ago. I was on a walking tour through 

 Devonshire, and the locality was Clovelly. Shortly 

 after quitting the village, I went along a narrow patli 

 winding up a hill ; one side of the path was guarded 

 by steep sandy rocks, and the other by a deep pre- 

 cipital descent. I had not got my insect net with 

 me, and, as usually happens in such cases, butterflies 

 were literally swarming. Clouded yellows, peacocks, 

 and scarlet admirals were flying in every direction, 

 and occasionally the white admiral was to be seen. 

 But these I had no means of catching. Suddenly a 

 wild rose flower gave a sort of plunge, and on looking 

 around for the cause, I saw an unmistakeable male 

 Apollo butterfly sitting there. I cautiously put my 

 hand over it, and enclosed it : it made not the 

 slightest resistance, and, not having box or bottle, I 

 transferred it uninjured to a bag I was carrying. It is in 

 perfect condition, and has safely passed the ordeal of 

 mites, which have destroyed some good specimens 

 during my absence. It is impossible to mistake its 

 identity ; and if the editor thinks fit, I will send him 

 a sketch of it, that he may see there is no mistake. — 

 H. C. Brooke. 



BOTANY. 



" The British Moss-Flora." — Dr. Braithwaite 

 has just issued Part VI. (price four shillings) of this 

 splendid work, devoted to the family Dicranaceae, 

 illustrated by figures and details of structures of 

 twenty-eight species. 



Trifolium stellatum, L. (Science-Gossip, 

 18S2, p. 279). — Your correspondent H. E. W. will be 

 glad to hear that Trifolium stellatum is still in fair 

 quantity in its old station at Shoreham, Sussex, 

 where I gathered it in August, 1SS1. At that time of 

 the year it was of course not in good condition. As 

 I am known to H. E. W. she can have specimens if 

 wished for. — Arthur Bennett, Croydon. 



"A New Potamogeton " (Science-Gossip, 1SS2, 

 p. 259). — I should like to supplement Mr. Jackson's 



