270 



SCIENCE-GOSSIP. 



only where they are needed, usually on rivers 

 where the level varies. In lakes, where the level 

 is nearly uniform, they built huts. These are in 

 the shape of a dome, more or less regular, contain- 

 ing two apartments, one under the soil, which 

 serves as a magazine for the storing of food, and 

 the other that may be called the ground floor, and 

 is used as a dwelling. The entrance is under the 

 water, and the beaver enters by diving. The ground- 

 floor communicates by secret passages with bur- 

 rows in the embankment, so that in case of attack 

 the animal can easily escape from its enemies. 



Beavers appear to associate for the sake of the 

 commonweal on the principle that unity is 

 strength. Their united efforts are necessary for 

 the construction of dams upon which their exis- 

 tence largely depends. As soon as they begin to 

 congregate they at once set to work, the young 

 with as much ability and assiduity as the old. 

 They are impelled to their work by a fatal 

 necessity, and they know how to build without 

 previous instruction. They always work on the 

 same uniform plan and with the same degree of 

 perfection. As soon as the beaver builds, it builds 

 well. Without previous discipline, with imper- 

 fect instruments, and however young, it performs 

 its part equally as well as the old and tried. 



It is remarkable that beavers, although so 

 ingenious and adroit, are unable to employ their 

 powers in any other direction than constructing 

 dams. They work in a circle beyond the peri- 

 phery of which they cannot go. Some argue that 

 the insufficiency of their organs is the cause of 

 this limitation. Feet and teeth, however perfectly 

 adapted for special ends, are not enough :, 

 intelligence and reason is necessary, and this they 

 lack. They cannot instruct other animals in their 

 several arts, even though they may have more 

 appropriate organs. The capacities of the beaver 

 are intransmissible to other animals. Man alone 

 is able to instruct, because he only is capable 

 of thought and reflection ; man alone employs 

 artificial tools. This is a distinction of profound 

 importance, and, unfortunately, is much overlooked 

 in present-day speculations in natural history. 



The following narrative by Cuvier is interesting 

 and instructive, as showing the powerful nature of 

 the instinctive propensities. He had a young 

 beaver recently taken from its mother, and as yet 

 quite blind. It was reared with all the care due to 

 its condition, and in the course of time it reached 

 the adult state. It was healthy and lively, and 

 evinced great attachment for its keeper. One day, 

 however, it fell into a sort of home-sick condition. 

 It ceased to eat, was restless, and appeared sad ; 

 its demise was gloomily apprehended, and every- 

 thing was done to avert such a catastrophe, 

 but all apparently to no purpose. A happy 

 thought struck Cuvier, and he caused wood, stones 



earth and water to be placed at the door of its hut, 

 in a word, all that was necessary for building 

 operations. The animal at once set to build with 

 its scanty materials, and from that time it revived 

 completely, and lived for many years. It made a 

 hut, in spite of having one. It prepared a maga- 

 zine and stored food, notwithstanding its sub- 

 sistence was well assured. It, therefore, acted 

 without motive, making preparations as if it had 

 been in its native wilds, and exactly like other 

 beavers. It never had the privilege of beaver 

 society, nor had it been taught the art of building, 

 yet its first performance was a master-stroke. We 

 observe in this the fatal, necessary, innate, perfect, 

 invariable, specific and intransmissible diagnoses 



of instinct. 



{To be continued.) 



THE ENTOMOLOGICAL CLUB. 



TV JR. G. H. Verrall, F.L.S., F.E.S.,was the host 

 at the meeting of the Entomological Club 

 held in the Entomological Saloon at the Holborn 

 Restaurant, London, on January 17th. Mr. Verrall 

 invited some forty-five visitors in addition to his 

 seven fellow members who constitute the Club. 

 One of the most interesting of the latter is Mr. 

 Samuel Stevens, F.L.S., etc., who on that evening 

 had been a member of the club for fifty-seven 

 years less three days, a most remarkable record. 

 After the supper, which followed the meeting, Mr. 

 Verrall, who, by the way, is one of the present 

 authorities on British Diptera, announced the in- 

 teresting fact that the missing minutes of the Club 

 had been recently restored to its custody, so forming 

 an unbroken record of the Club meetings since 

 1836. Founded in 1826, reference occurs to most 

 of the leading British entomologists during the 

 period. Since then we are pleased to note that 

 Mr. Verrall has been elected President of the Ento- 

 mological Society of London for the current year. 



The Satellites of Mars, discovered byProfessor 

 Asaph Hall, on August nth and i8lh, 1877, with 

 the twenty-six-inch Washington achromatic, are 

 hopelessly beyond the powers of common telescopes, 

 seeing that when favourably near the earth they 

 only equal stars of about 12th magnitude, the inner 

 one being a trifle the brightest. Phobos, the 

 nearest one, is less than a diameter of Mars from 

 his surface and makes a complete revolution of its 

 orbit in a bare 7h. 40m., producing the singular 

 effect of rising in the west and setting in the east. 

 This satellite remains above the horizon, as Pro- 

 fessor E. Ledger long ago pointed out in one of the 

 Gresham College lectures, for five and a-half hours, 

 and is often eclipsed during fifty-three minutes 

 of that time. The outer satellite, Deimos, has a 

 period of nearly 30I1. 18m., travelling in a path 

 about three diameters of Mars from his surface. 

 This moon rises in the east, but remains above the 

 horizon for sixty hours at a time, during which 

 interval it could be eclipsed twice, spending two 

 or three hours buried in the planet's shadow. 



