March 8, 1877J 



NATURE 



415 



from the usual summer appearance. The occurrence is perfectly 

 explained by the circumstance that the temperature of water in 

 the Lake of Geneva was this year higher by two degrees than 

 the average temperature for many years, which is 6" '3 Cels. for 

 December and 4" "9 for January. 



A New Sponge. — Prof. E. Perceval Wright describes {Proc. 

 R, Irish Acad., vol. ii,, ser. 2, part 7) a beautiful little sponge 

 found growing on the fronds of some species of Red Seaweeds 

 from the coasts of Australia, of which we give the accompanying 

 illustration. The largest specimens measure not three milli- 

 metres in height. The sponge consists of three distinct and well- 

 marked portions : firstly, a small basal disk ; secondly, an elon- 

 gated stem, on the summit of which expands the third portion, or 

 capitulum. The disk is button-shaped^ flat, and is formed of an 

 irregular homy framework, twice to three times as broad as the 

 stem. The stem varies in height, and presents the appearance, 

 in some cases, of a series of margined rings, some twenty in 

 number, fastened together one on 

 the top of the other ; in others the 

 margins of the rings will be more 

 prominent, and the bodies of the 

 rings will be, as it were, more 

 deeply sunk. In both these cases 

 the horny framework is of a more 

 or less evenly latticed character, 

 the longitudinal lines of the lattice 

 being very prominent. The head 

 portion, in its natural state, pro- 

 bably presents a more or less spheri- 

 cal form, perhaps slightly flattened 

 on the summit, with an indication 

 of being divided into four nearly 

 equal parts, the open space between 

 these leading into the body-cavity 

 of the sponge. In some of the 

 specimens the head portion nearest 

 to the stem seems to have been 

 formed of a somewhat denserframe- 

 work than the upper portion, so 

 that while being pressed this upper 

 portion has been fractured across. 

 The framework here is of a densely- 

 reticulated kind, in appearance re- 

 minding one of the reticulated net- 

 work of the intracapsular sarcode 

 in Thalassolampe, or of the tissues 

 met with in some Echinoderms. 

 This sponge has been called Kalli- 

 spoHgiaarcheri. Tire wonderful mimetic resemblance which it bears 

 to some Crinoid-forms can scarcely be overlooked. Leaving the 

 texture and composition of the skeleton mass for the moment out 

 of view, and simply looking at its outline — the circular disc-like 

 base, the stem — the profile of which is absolutely the same, 

 except as to size, as that of the pentacrinoid stage of Antedon 

 rosaceus, and the slightly cleft head, the resemblance is very 

 great. Fo far as is known, this is a unique case among the 

 sponges, and one is left to wonder what may be the tiny enemies 

 from which Kallispongia archeri, by this complete disguise, con- 

 ceals itself. 



Wild Dogs on the Obi. — An interesting occurrence of dogs 

 which have reverted to the wild state is reported by M. Poliakoff 

 from the neighbourhoods of Soorgoot on the Obi, and Tobolsk. 

 The size of these animals is ^somewhat larger than that of 

 the dogs of the locality, but less than that of wolves ; their 

 habits being rather remarkable the inhabitants would not ac- 

 knowledge them to be common dogs, and the hunters preserved 

 the skins of the individuals they happened to kill, as rare samples 



KitUispoH^ia. 



of unknown animals. M. Poliakoff could not, however, detect 

 in the skins he describes any deviations from the common dog 

 type, except the larger size, and perhaps a somewhat greater 

 length of body, with comparatively shorter legs (at Tobolsk). 

 But the habits of these animals arc certainly wolf-like ; they 

 inhabit woods and live by hunting, which they carry on in com. 

 panics. Ten individuals were thus well-known at Soorgoot as 

 hunting in company the wild reindeer, and latterly they ap- 

 proached the settlements, causing a panic among the inhabitants 

 by the ravages they made among cattle. They hunted always 

 together, assailing their prey simultaneously. They are reported 

 also to be far more voracious than wolves, and their habits, 

 M, Poliakoff observes, resemble much those of the red highland 

 wolf ( Canis alpinus) of Eastern Siberia. 



The Woodpecker. — At the session of the German Orni- 

 thological Society, on February 8, Prof. Altum gave an in- 

 teresting address on the ordinary woodpecker, embodying a 

 portion of the results of over seven years' observation. With 

 regard to the question of how the woodpecker finds the trees 

 inhabited by insects, he had noticed that it almost invariably 

 resorted to such trees as bore the diseased look consequent upon 

 the presence of insects, manifested by the smallness and fewness 

 of the leaves, the absence of the usual fresh colour of the bark, 

 &c. In some cases it is deceived, especially where new varieties 

 of trees have been set out. When it has detected a hole bored 

 in the bark by insects, it follows the course of the passage under 

 the bark by a gentle tapping with its bill, until it reaches the 

 place where the larvas are situated, when, by tearing off large 

 portions of bark, its food is laid bare. Among the insects 

 not eaten by the woodpecker are such as the Cerombyx heros, 

 which bores too deep into the wood, or small insects such as 

 the Bostichida;, living in the bark of the pine tree, which is dif- 

 ficult to penetrate. The presence of the woodpecker is good 

 for a forest, in so far as it destroys the insects upon the trees. It 

 however injures the latter frequently by tearing off large pieces 

 of bark, and indirectly by eating the useful wood-ants. The 

 statement that woodpeckers made incisions in trees free from 

 insects, for the purpose of sucking the sap, was disproved by 

 Prof, Altum, on ground of repeated observations. 



Sagacity of a Lobster, — A few days ago, at the Rothesay 

 Aquarium, a tank containing flat fishes was emptied, and a 

 flounder of eight inches in length was inadvertently left buried 

 in the shingle, where it died. On refilling the tank it was 

 tenanted by three lobsters (Ilomarus marinus), one of which is 

 an aged veteran of unusual size, bearing an honourable array of 

 barnacles ; and he soon brought to light the hidden flounder, 

 with which he retired to a corner. In a short time it was noticed 

 that the flounder was non est. It was impossible the lobster 

 could have eaten it all in the interim, and the handle of a net 

 revealed the fact that, upon the approach of the two smaller 

 lobsters the larger one had buried the flounder beneath a heap of 

 shingle, on which he now mounted guard. Five times within 

 two hours was the fish unearthed, and as often did the lobster 

 shovel the gravel over it with his huge claws, each time as- 

 cending the pile and turning his bold defensive front to his com- 

 panions. 



The Influence of Temperature on the Nerve- and 

 Muscle-Current. — M. Steiner has proved {Reickert's Archiv) 

 that the electromotive force of the nerve- current from 2* up- 

 wards, is greater the higher the temperature, that it reaches a 

 maximum between 14° and 25°, and at higher temperatures 

 decreases again. The force of the muscle-current is likewise, from 

 5° upwards, greater the higher the temperature ; it has its maxi- 

 mum between 35° and 40°, and at higher temperatures becomes 

 less again, till, when rigidity sets in, it is almost nil. Thus, for 

 the nerve and muscle- current, as well as for other functions of 



