Juilt 2J, 1878] 



NATURE 



227 



moth worked its way at once out of the'slit. The wings 

 at this time being very small and flabby, and the shoulders 

 being alternately much raised, the points stuck up far 

 enough to cut or saw through the cocoon. The wings 

 were at first of a deep buff yellow, but in half an hour 

 after they began to expand and to turn green. The black 

 points can be detected when the wings are fully expanded, 

 not being entirely covered by the hairs at the base of the 

 wing. In this case no fluid was seen to exude from the 

 mouth, and the cocoon was perfectly dry. The black 

 points are seen, when magnified, to hare the form of a 

 rude saw, and Dr. Packard -proposes for them the term 

 sectores coconis. The cocoon-cutters were found in every 

 other species of the sub-family y?//a« that was .examined ; 

 in Telea polyphemtis they are large and well-developed ; 

 they are rather small in Callosamia protttethea, Platysamia 

 cecropid, P. Gloverii, Sainia cynthia, an Attacus from 

 Nicaragua, and Attacus amazonia, Pack,, from Pebas, 



Peru ; large and well-marked in the European Saturnia 

 pavonia-minor and Etidromis versicolora. In Bombyx 

 mori the spines are not well-marked, and they are quite 

 different from those of the Attaci. They are three sharp 

 points, being acute angles of the pieces at the base of the 

 wing. No such spines are present in Eacles imperialis. 

 In the accompanying cut a represents a front view of a 

 specimen of Actias lima which came out of the cocoon 

 and died with the wings not expanded ; the shoulders 

 are elevated, and the rudimentary wings hanging down ; 

 ,/« J- the scatum, s the cocoon-cutter,^ the patagium. B 

 represents another specimen with fully-developed wings ; 

 m s the scatum, s t the scabellum of the meso-thoracic 

 segment, s the cocoon-cutter, which is evidently a modi- 

 fication of one of the pieces at the base of the fore-wings ; 

 it is surrounded by membrane, allowing free movement. 

 C and D are modifications of the spine or sector coconis 

 considerably magnified, showing the five or six irregular 

 teeth on the cutting edge, the spine being sharp, curved, 

 and conical. It will be seen that it acts like a rude saw. 



Fear of Snakes in Primates.— Mr. A. E. Brown 

 has recently made experiments in the Philadelphia 

 Zoological Garden, in pursuance of those of Mr. Darwin. 

 He coiled a dead snake in a newspaper, so as to be 

 easily capable of coming loose, and set it on the floor of 

 a cage containing a great variety of monkeys. It was 

 instantly carried off by a leading spirit, but in a few 

 seconds the paper became unfolded and the snake was 

 exposed. The monkey instantly dropped it and went 

 away, but with a constant look behind. The other 

 monkeys, perceiving the snake, approached, step by step, 

 and formed a circle round it six or eight feet in diameter. 

 None approached except one Macaque, who cautiously 

 made some snatches at the paper. At this moment a 

 string which had been attached to the snake's tail was 

 gently pulled ; the snake moved, consequently, and the 

 monkeys fled precipitately, with great chattering and 

 screaming. Some time after they gradually returned to 

 their former position, and they continued for some hours 

 showing both intolerable fear and a strange attraction. 

 The same monkeys had no fear of a tortoise or a small 



dead alligator. The same snake was then shown to 

 mammals of other orders, but none of them showed any 

 especial interest. It is seen that the same dread of 

 snakes is shared by the human species, especially women. 

 Mr. Brown was able to trace, in the actions of a woman 

 who was deaf and dumb, very similar fear, attraction, 

 and repulsion to that shown by the monkeys. Is this a 

 relic of early struggles for existence with an enemy 

 whose bite produced results very different from that of 

 other animals, and exposed mankind to a death lingering 

 and horrible ? 



The Fertilisation of Eggs of the Lamprey. — 

 We have frequently referred to the great progress of 

 researches into the actual phenomena of fertilisation, 

 especially those of Hertwig. Ernst Calberla, of Freiburg, 

 is another most earnest pursuer of this subject, and he 

 has followed the fertilisation of the lamprey. His views 

 corroborate very strongly those of Hertwig, with some 

 additional particulars. He finds a very distinct external 

 micropyle, with a channel in the yolk leading into the 

 ovinucleus {Eikerii), which is the residuum of the germinal 

 vesicle. The spermatozoon which is so fortunate as to 

 find the micropyle, enters it and gives rise to the sperm- 

 nucleus {Sper7nakern), which appears twenty-six seconds 

 after the entrance of the spermatozoon into the micropyle. 

 In a minute and a half altogether, the cleavage-nucleus 

 {Furchungskern) is seen. After five hours the first cleavage 

 furrow arises, at the spot where the micropyle was 

 situated. In the Zeitschrift filr wissenschaftliche Zoologie, 

 vol. XXX. part 3, Calberla gives a most interesting account 

 of his procedure and observations, and reviews the work 

 of other investigators, giving a capital bibliography which 

 is of value to those interested in such a rapidly expanding 

 subject. 



GEOGRAPHICAL NOTES 

 Admiral Sir George Back, F.R.S., died on Sunday 

 at the age of eighty-one years. He entered the Royal 

 Navy when twelve years old as a midshipman on board 

 the Arethusa, and in 1818 joined a vessel under the com- 

 mand of Sir John Franklin, whom he accompanied on his 

 expedition overland from Hudson's Bay to the Coppermine 

 River, having already taken part under Capt. Buchan in 

 his perilous voyage of discovery made to the neighbour- 

 hood of Spitzbergen. In the spring of 1825 Lieut. Back 

 again accompanied Sir John Franklin on his second ex- 

 pedition to the Arctic regions for the purpose of co- 

 operating with Capt. Beechy and Capt. Parry in their 

 simultaneous efforts to ascertain from opposite quarters 

 the existence of a north-west passage. Full details of 

 this voyage will be found in Franklin's "Narrative of 

 a Second Expedition to the Shores of the Polar Sea." 

 Back was again appointed in the spring of 1833 to con- 

 duct the expedition fitted out for the purpose of seeking 

 and relieving Sir John Ross, who h:-d gone out nearly 

 four years previously in quest of the north-west passage. 

 A full account of the results of that hazardous enterprise, 

 in the course of which he discovered the river which has 

 since borne his name, Capt. Back gave to the world in 

 his "Narrative of the Arctic Land Expedition to the 

 Mouth of the Great Fish River and along the Shores of 

 the Arctic Ocean in 1833-35." In 1836 Capt. Back 

 sailed in command of another expedition to the frigid 

 zone. The details of this expedition, in the course of 

 which he reached Frozen Strait, almost within sight of 

 Repulse Bay, were published by Capt. Back in his 

 "Narrative of the Expedition in Her Majesty's Ship 

 Terror, Undertaken with a view to Geographical Disco- 

 very, in 1836-37." In 1857 he obtained flag rank, but 

 had not been afloat since that date. In 1837 Back had 

 awarded to him the gold and silver medals of the Geo- 

 graphical Society. He also was honoured by the gold 



