July i 9( 1883] 



NATURE 



If the eggs of a wild duck are placed with those of a tame 

 one under a hen ' to be hatched, the ducklings from the former, 

 on the very day they leave the egg, will immediately endeavour 

 to hide themselves, or take to the water if there is any near, 

 should any person approach, whilst the young from the tame 

 duck's eggs will show little or no alarm, indicating in both cases 

 a clear instance of instinct or " inherited memory." 



4, Addison Gardens, July 16 John Rae 



Clouds 



The following notes of a cloud action, which, so far as I am 

 aware, is not common, may be considered worthy of record. 



The occurrence took place at Chatham at about 1 p.m. on 

 Sunday the 1st inst., and attracted attention more particu- 

 larly from its following a week of strong electrical disturbance 

 in the neighbourhood, accompanied by two fatal results. 



At the hour named above, and apparently at a considerable 

 height, certain semi-transparent clouds arranged themselves in 

 thin columns at right angles to each other, some of the columns 

 giving off shoots throughout their length, in shape somewhat 

 resembling blades of grass. Whenever fleecy clouds passed 

 between the foregoing formation and the earth, they were quickly 



NPtfs 



broken up into small, attenuated components which gradually 

 reunited on getting out of the influence ; but on one occasion a 

 very small cloud thus acted upon set itself in the form of a right 

 angle also and remained so. K. Y. Armstrong 



July 7 



Extraordinary Flight of Dragon-Flies 



An English gentleman writing from Malmo, in Sweden, on 

 July 3, says :— 



" On Sunday, June 24, we had an extraordinary flight of the 

 Trollsldnda (Libellula tjiindriiuaculata, Linn.), ... a brown 

 dragon-fly an inch and five-eighths long and three inches from 

 tip to tip of the wings. . . . They passed over or through the 

 town and neighbourhood for about half an hour in the after- 

 noon. The next day about I o'clock they reappeared for more 

 than an hour, but on Tuesday the 26th, at 7.30 a.m., they again 

 began in millions, and notwithstanding the wind had shifted to 

 the south during the night, they held the ;ame course from 

 north-west by west, heading south-east by east. The street--, 

 shipping, and every place were full of them. They did not fly 

 very high, and seemed to avoid going into open doors and 

 windows. Some hundred or so alighted on the gooseberry 

 bushes, apple and pear trees in this garden, but never touched 

 the fruit. I observed one sitting on the dead tip of an apple- 

 twig, and 1 pushed it off with my stick thirteen times, the insect 

 returning each time after flying away about five or six yards. 

 . . . The flight ended that night about 8 p.m., having been 

 incessant for more than twelve hours. On the 27th they 

 appeared again about noon, flying the same course, but in much 

 reduced forces. Each day since I have seen a few, but very 

 few. . . . The papers say they were observed in all southern 

 and Central Sweden, and in many places in Denmark, and they 



1 I mention a hen as foster-mother because the ducklings can have no 

 instinctive knowledge of any note of alarm or warning she may give. 



swarmed about the ships in the Sound. With their disappear- 

 ance carre the hot weather." 



The foregoing extracts seem to me worthy of record in 

 the pages of Nature, and I accordingly forward them with 

 that view. Alfred Newton 



Magdalene College, Cambridge, July 1 1 



Sheet Lightning 



We had here last night a violent rain and lightning storm 

 without thunder. The lightning was very vivid and ince sant, 

 and seemed nearly overhead, but there was no sound but that of 

 rain. We are near the crest of the Apennines, and the storm 

 seemed to have gathered along that crest, having been preceded 

 by a furious sirocco suddenly supervening on a north-west wind. 



I have twice before witnessed the same phenomenon of elec- 

 trical storms with vivid lightning overhead and no thunder. 

 Both instances occurred on the abrupt edge of the Montenegrin 

 highlands, where they fall off into the low, wide plains of the 

 Scutari district, and where thunderstorms are more common than 

 in any other country I have ever visited. On these nights we 

 were encamped on the edge of the hill country, on broken rocky 

 land, with much low scrubby vegetation, but the lightning was 

 so incessant and vivid that we were able to walk about, choosing 

 our way amongst the stones and shrubs as readily as by daylight, 

 the intervals between the flashes being, I should judge, never 

 more than a minute, while much of the time they seemed abso- 

 lutely continuous, the landscape being visible in all details under 

 a diffused violet light. Looking overhead the movements of the 

 lightning were easily discernible, the locality of the discharges 

 varying from one part of the vault to another in a manner which 

 it was impossible to confound with the reflection of lightning 

 from a distance. Like the storm of last night those were fol- 

 lowed by copious rain, but not a single peal of thunder was 

 heard during the whole night. W. G. Stillman 



Cutigliano, Pistoiese Apennines, July n 



■p\R. BERTHOLD tells us in his preface that he was 

 *-^ induced by his discovery of the processes of fructi- 

 fication in Erytlirotrichia obscura to study the small but 

 interesting group of the Bangiaceae, in the knowledge of 

 which so many gaps still existed. The Zoological Station 

 at Naples afforded him every facility for carrying on his 

 researches on these algae, not only in what may be called 

 their wild state, but also under cultivation. To these 

 advantages may be added, although in an inferior degree, 

 that of the use of a great number of dried specimens. 

 The results of his two years' study are embodied in the 

 work mentioned at the head of this notice. 



The small group of algae, now included by Dr. 

 Berthold under the general name of Bangiaceae, consists 

 of the three genera, Bangia, Porphyra, and Erythro- 

 trichia ; under the last genus are included Bangia 

 ciharis, and B. ceramicola of Harvey (" Phyc. Brit.," Pis. 

 ccexxii. and ccexvii.). To these genera may probably be 

 added Goniotrichum. 



The exact systematic position of these algae has, from 

 the fact that little was known of their fructification, been 

 hitherto uncertain. While their red colour induced Cohn, 

 Thuret, and Bornet to place them with the Florideae ; 

 other algologists, among whom may be mentioned J. 

 Agardh, Ktitzing, Harvey, and Zanardini, grounding their 

 opinion on the structure of the vegetative thallus, have 

 classed them with the Chlorosperms. 



For the first information relative to the fructification of 

 the Bangiaceae, we are indebted to Derbes and Solier, 

 who had discovered in Bangia fusco-purpurca and B. 

 lutea two different kinds of fructification, namely, the 

 " common spores " and antheridia. Then followed the 

 researches of Nageli, Thuret, and Janczewski on Porphyra. 

 Janczewski had actually discovered and described the 

 carpospores of Porphyra, to which he gave the name of 



' " Die Bangiaceen des Golfes von Neapel." Eine Monographic von Dr. 

 G. Berthold. Fauna und Flora des Golfes von Neapel. (Leipzig: Wilhelm 

 Engelmann, 1882.) 



