July 1, 1S66.] 



SCIENCE-GOSSIP. 



159 



ZOOLOGY. 



Pulsations of Mollusks.— It is well known that 

 during hybernation our laud pnlmoniferous gastero- 

 pods experience an almost total cessation of the action 

 of the heart. On subjecting a few of our common 

 snails, some time ago, to considerable changes of 

 temperature, I found the circulation to be increased 

 or diminished to an extraordinary degree. The 

 results here given may, perhaps, induce others 

 interested in conchology to make more complete 

 investigation. Zonites radiatulus, when laid upon a 

 deal table, in a room in which the thermometer 

 stood at 62°, showed 52 pulsations a minute. It 

 was then placed upon the palm of the hand, and in 

 the course of a short time the action rose to 10S — 

 more than double its previous rate. Helix hyhrida, 

 a much larger animal, showed under similar circum- 

 stances a variation from 49 to 92. Zonites alliarius 

 ranged from 72 to 110. This animal was then placed 

 in a small platinum cup, and floated upon water 

 drawn from a tap in the room. The action of the 

 heart was suddenly checked, aud soon fell to 29 

 pulsations a minute, a rate which was maintained 

 until the animal was removed from its cool quarters. 

 In this instance a range of about 45° of temperature 

 caused a variation of from 29 to 110 pulsations — a 

 ratio of one to four nearly. I believe it has never 

 yet been ascertained whether these animals have, 

 like mau, the power of generating heat, so as to 

 maintain a nearly equable temperature of the body, 

 whatever the temperature of the surrounding 

 medium, or whether, as in the case of some cold- 

 blooded animals, considerable variation of internal 

 heat ensues. It would be interesting, too, to know 

 whether our more hardy mollusks, such as Helix 

 fusca and Vitrina pettticida, which are to be found 

 moving about with energy even on frosty mornings, 

 are subject to the same affections of the heart as 

 have been mentioned above. — C. Ashford, Grove 

 House, Tottenham. 



Rooks Resting on the Ground. — One evening 

 some years since, I was returning from a visit to a 

 friend in the country, when my attention was 

 directed to some dark objects lying on the bare 

 ground at the further end of a field that adjoined 

 the road. The distance, however, aud the twilight, 

 prevented my ascertaining their nature, but while I 

 was looking at them a labouring man came up, who 

 informed me that they were rooksrestiugforthenight, 

 that he had frequently seen them at the same place 

 not only when he passed in the evening, but also in 

 the early morning, in going to his daily labour. As 

 I did not have another opportunity of witnessing, 

 nor ever heard of, such an apparently unusual habit 

 of these birds, I know not whether it is general 

 with them, and therefore make a note of it for a 

 corner in Science Gossip. — /. B. A. 



Rook stealing Eggs.— Having for some weeks 

 past been losing eggs from the hens' nests near my 

 house, and suspecting the thief to be a magpie or 

 crow, I made an artificial nest in a hedge-trough, 

 placing two eggs in it. I then stuck in the ground 

 some bushes, making a path about six inches in 

 length up to the nest, and set a gin iu it. On visit- 

 ing my trap the next morning, I was surprised to 

 find it held an old rook. There could be no mistake 

 in the identity, others saw the bird besides myself. 

 I am confident this rook could not have hopped 

 accidentally into the gin ; he must, therefore, have 

 been the thief. Is it not an uncommon occurrence 

 for rooks to suck eggs ? — N. E. C. 



Tree-Sparrows. — I have found two tree-sparrows 

 (Passer montanus) in sand-martins' nests near 

 Leamington, a circumstance which may be of 

 interest to some of your readers.— 27. G. TFheler. 



Suicide among the Scorpions. — Captain Pasley, 

 R.A., mentioned that he had repeatedly tried the 

 experiment of surrounding the scorpion with a ring 

 of fire, and that it had invariably stung itself to 

 death. The fiery circle was about fifteen inches in 

 diameter, and composed of smouldering ashes. In 

 every instance the scorpion ran about for some 

 minutes, trying to escape, and then deliberately 

 bent its tail over its back, inserted the point of its 

 sting between two of the segments of its body, and 

 speedily died. This experiment was repeated seven 

 or eight times, and always with the same results, so 

 that a further repetition would have been but a useless 

 cruelty. The heat given out by the ashes was very 

 trifling, and not equal to that which is caused by the 

 noontide suu — a temperature which the scorpion 

 certainly does not like, but which it can endure 

 without suffering much inconvenience. Generally 

 the scorpion was dead in a few minutes after the 

 wound was inflicted. — Wood's " Homes without 

 Hands:' 



Sting of Sea Anemones.— I cannot agree with 

 your correspondent, M. D. P., in the supposition 

 that anemones only sting "when out of health," 

 for it was only a few weeks since that I noted a fact 

 which leads me to a contrary conclusion. I was 

 down on the rocks at low tide, and determined, on 

 seeing a fine Anthea, to test its stinging powers, 

 and very soon received a sensible proof on the back 

 of my hand between the little and thud fingers, not 

 only from the pain experienced, but by the white 

 spots produced, like those from the sting of a 

 nettle. I certainly had no power of examining the 

 tongue or feeling the pulse of this anthea, but, 

 judging from its general appearance and com- 

 plexion, and from seeing it in its native home, 

 I should have no hesitation in pronouncing it to 

 be in perfect health, yet possessing the urtieating 

 power. — /. G. B. 



