112 



KNOWLEDGE. 



March, 1911. 



closely together in the sheath this is not evident owing to their 



compression, but when relie\ed from the pressure, and a few 



only adhering together, they form short cylinders, with 



rounded ends or almost circular collections (Figures C, D). 



In the older specimens the wall of the filament is greatly 



thickened and shows a distinct lamellose structure, the outer 



layers frequently split off, and where injured by sharp bending 



become broken, ragged and almost fibrous in character. In 



these cases the protoplasm is reduced in amount, loses its 



bright colour, becoming brownish, and mostly collects into the 



masses already described, as at D. The plant differs from the 



more common species of British Lyngbyeae in two respects. 



It is much larger than the majority; at E is represented 



on the same scale Lyngbya iniiiitiaia Kutz, a rather 



small but plentiful species ; the filaments in this case are 4m 



in diameter ; while those from the Seychelles are from 



30 to 35m, without the sheath. Dr. Cooke gives 25-30m 



without sheath for L. acstuarii, a large British species 



found in brackish and salt water, but 7-10m is the average 



diameter of the greater number. Also the protoplasmic discs 



are very much thinner than is usual in our own familiar 



species ; here they average only about 2m at the edge, and 



sometimes in young specimens less, looking under moderate 



magnification like discs of paper filling the thick walled tube. 



The literature available on these lowly members of the 



\egetable kingdom is very scanty, and scattered through 



pamphlets and proceedings of various societies. If any reader 



of " Knowledge " can add information to what I have 



supplied, it would, no doubt, be welcome to many interested 



in the studv of the lower .^Igae. 



J. b. 



yUEKETT MICROSCOPICAL CLUB.— January _:4th. 

 1911, Professor E. A. Minchin, M.A., President, in the chair. 

 Through the courtesy of Mr. E. M. Nelson, a note on the 

 " Amician test " (see " Knowledge," 1910, page 325), by Mr. 

 F. J. Keeley, of Philadelphia, was read. Mr. Keeley possesses 

 a balsam-mounted slide, labelled "XaviciiUi Atnicii, Florence, 

 Italy. P'rom Professor Ainici to C. .V. Spencer." It is a 

 fresh-water gathering and contains, besides a large proportion 

 of typical A', rlioinboidcs, a few \'al\es under 50m in length 

 which form a class by themselves on account of their extreme 

 delicacy and transparency. 1 he author gives measurements 

 of twenty valves and the number of transverse striae 

 per -01 millimetre in five typical specimens. From these 

 particulars, Mr. Nelson considers the identitv- of the .Amician 

 test with the "English A', rlioinboidcs" finall\- determined. — 

 Mr. C. F. Rousselet, F.R. M.S., described and exhibited prepara- 

 tions and drawings of three new species of Rotifera. These 

 are Anuracopsis navicida, BracJiionus sataniciis and 

 Brachionus havanaensis. These will be fully described and 

 figured in the next issue of the Club's Journal. — Mr. R. T. 

 Lewis, F'.R.M.S., read a paper " On the larvae of Mantispa." 

 He referred to the great apparent similarity between mature 

 specimens of the Mantidae family and those of the 

 sub-family Mantispidae. The wing structure, however, 

 places the Mantis family amongst the Orthoptera and 

 the Mantispidae with Neuroptera. The Mantidae construct 

 a curious capsule or ootheca in which the eggs are 

 laid in symmetrical rows and are entirely covered in from 

 \iew, while the eggs of Mantispa are laid singly, each mounted 

 on a slender stalk. On first emerging from the egg the young 

 Mantis closely resembles the adult except as to size, colour, 

 and the absence of wings. In Mantispa, the larva on emerging 

 bears not the slightest resemblance to the perfect insect (a full 

 description with drawings and exhibition of specimens was 

 given). On leaving the egg the larva bores its way into 

 the ovisac of a spider and feeds upon the eggs, or young, 

 until it has changed its skin a second time. The legs then 

 disappear, the head is reduced in size and loses its antennae, 

 and the larva becomes a helpless fleshy grub, which presently 

 spins a cocoon. Emerging from this it passes through two 

 more moults and becomes a full-grown neuropterous 

 Mantispa. 



Mr. H. Ciunnerx-, of .Acomb, York, sent for exhibition a 

 number of preparations, chiefly botanical, some especially fine 

 of nuclear di\ision in Lilinm. These were shown under a 



number of microscopes kindly lent by Mr. C. Baker. Mr. 

 Gunnery also sent a mimber of lantern slides, mostly photo- 

 micrographs. These were projected on to the screen. The 

 thanks of the meeting were accorded to Mr. Gunnery and to 

 Mr. Baker. 



ORNITHOLOGY. 



By Hl-gh Bovm Watt, M.B.CJ.C. 



SPEED OF FLIGHT OF BIRDS ON MIGRATION.— 

 Giitke in his well-known work on " Heligoland as an 

 C)rnithological Observatory" (1895). has a chapter on the 

 velocity of flight of passing birds, in which some estimates of 

 so high a value were given as to cause not a little surprise. 

 The speed of Hooded Crows was stated to be one hundred 

 and eight geographical miles per hour, and that of the Northern 

 Bluethroat as one hundred and eighty: and Plovers, Curlews, 

 and Godwits, were noted in numbers as crossing the island, 

 over a measured distance, at a rate of nearly four miles in one 

 minute. 



A series of observations made in the autunm of 1909, under 

 the direction of Dr. J. Thienemann, at the Migration Observa- 

 tory at Rossittcn (East Prussia), give very different results 

 from Gatke. At Rossitten allowances were made for the 

 factors influencing the birds (such as wind), and the following 

 figures arc the average results for the species named, calculated 

 to English miles. (See British Birds, January, 1911, 

 page 260.) They are here placed in order, from the lowest 

 speed upwards : — 



Sparrow- Hav.'k ... 25t miles Brambling ... 52i miles 



Lesser Black- Siskin ... ... 34 ij- „ 



backed Gull ... 31 ,, Linnet ... ... 34 J ,, 



Great Black-liacked Peregrine Falcon... 37 



Gnll 3U .. Crossbill 37?, ,. 



Hooded Crow ... 31f „ Jackdaw 38J 



Rook iZi „ Starling 46;\ „ 



Chaffinch iZ'i „ 



There are curious contrasts in these figures, and it seems 

 clear that no fixed conclusions can be drawn until many 

 further observations have been made and coordinated. 



UNTOWARD FATE OF AN EGG OF THE GREAT 

 AL'K [.Ale a iinpcnnis). — Mr. E. Bidwell, in the current 

 number of the Ibis (January 1911, page 184), tells a curious 

 story of disregard of an ornithological treasure in the form of 

 an egg of this extinct species. For about twenty years Mr. 

 Bidwell has known of the existence of an egg in a small 

 museum at Dinan, France. In September last, along with 

 Mr. Henry Stevens, he visited the place with the intention of 

 photographing the egg. The Castle (lately a prison) was 

 found to have been made into a museum, but not many 

 natural history specimens were exhibited, and the curator 

 knew nothing of any Great Auk's egg being in the collection. 

 The birds and other animals had been considered not worth 

 moving, and on the pre\'ious afternoon had all been stored in 

 an attic, at the Hotel de Ville. There, on the floor, amidst a 

 jumble of stuff'ed birds, the remains of the Great Auk's egg 

 were found. Mr. Stevens photographed the two largest 

 fragments, and his photographs were shown by Mr. Bidwell, 

 at a recent meeting of the British Ornithologists' Club. The 

 price of a good specimen of this egg at present is about £250. 



THE CENTRAL NEW GUINEA ORNITHOLOGICAL 

 EXPEDITION.— The British Ornithologists' Union expedition 

 has suffered a further loss by the compulsory retiral. through 

 ill-health, of Mr. Walter Goodfellow, from the leadership. 

 Capt. C. G. Rawling, surveyor to the party, has been 

 appointed to take command. The arduous character of the 

 undertaking rec"i\-es further emphasis from the last report 

 published (Ibis, January 1911, page 186). The camp and 

 surrounding country had been completely flooded by the River 

 Mimeka, and when the floods subsided the whole camp became 

 a bog. Headquarters were then remo\ed to the Waitakwa 

 River for a further advance. 



IRISH BIRDS— NEW RACES OR FORMS.— Visitors to 

 the Natural History Museum, South Kensington, at present. 



